U.S. patent application number 12/634259 was filed with the patent office on 2010-04-08 for epoxy resin composition and cured article thereof, semiconductor encapsulation material, novel phenol resin, and novel epoxy resin.
This patent application is currently assigned to DAINIPPON INK AND CHEMICALS, INC.. Invention is credited to Ichirou OGURA, Yutaka SATO, Yoshiyuki TAKAHASHI.
Application Number | 20100087590 12/634259 |
Document ID | / |
Family ID | 36941232 |
Filed Date | 2010-04-08 |
United States Patent
Application |
20100087590 |
Kind Code |
A1 |
OGURA; Ichirou ; et
al. |
April 8, 2010 |
EPOXY RESIN COMPOSITION AND CURED ARTICLE THEREOF, SEMICONDUCTOR
ENCAPSULATION MATERIAL, NOVEL PHENOL RESIN, AND NOVEL EPOXY
RESIN
Abstract
The object of the present invention is to provide an epoxy resin
composition capable of realizing low dielectric constant and low
dielectric dissipation factor, which is suited for use as a latest
current high-frequency type electronic component-related material,
without deteriorating heat resistance during the curing reaction. A
phenol resin, which has the respective structural units of a
phenolic hydroxyl group-containing aromatic hydrocarbon group (P)
derived from phenols, an alkoxy group-containing condensed
polycyclic aromatic hydrocarbon group (B) derived from
methoxynaphthalene and a divalent hydrocarbon group (X) such as
methylene and also has a structure represented by -P-B-X- wherein
P, B and X are structural sites of these groups in a molecular
structure, is used as a curing agent for the epoxy resin, or a
phenol resin as an epoxy resin material.
Inventors: |
OGURA; Ichirou;
(Ichihara-shi, JP) ; TAKAHASHI; Yoshiyuki;
(Ichihara-shi, JP) ; SATO; Yutaka; (Chiba-shi,
JP) |
Correspondence
Address: |
WESTERMAN, HATTORI, DANIELS & ADRIAN, LLP
1250 CONNECTICUT AVENUE, NW, SUITE 700
WASHINGTON
DC
20036
US
|
Assignee: |
DAINIPPON INK AND CHEMICALS,
INC.
Tokyo
JP
|
Family ID: |
36941232 |
Appl. No.: |
12/634259 |
Filed: |
December 9, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
11817535 |
Sep 9, 2008 |
|
|
|
PCT/JP2006/303902 |
Mar 1, 2006 |
|
|
|
12634259 |
|
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|
Current U.S.
Class: |
524/540 ;
525/529; 528/212 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 2924/3011 20130101; H01L 23/293 20130101; C08G 16/02 20130101;
H01L 2924/0002 20130101; C08L 63/00 20130101; C08G 59/621 20130101;
H01L 2924/00 20130101 |
Class at
Publication: |
524/540 ;
525/529; 528/212 |
International
Class: |
C08L 63/00 20060101
C08L063/00; C08G 65/38 20060101 C08G065/38 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 2, 2005 |
JP |
2005-057393 |
Mar 2, 2005 |
JP |
2005-057394 |
Sep 5, 2005 |
JP |
2005-257056 |
Claims
1. An epoxy resin composition, comprising an epoxy resin and a
curing agent as essential components, wherein the curing agent is a
phenol resin which has respective structural units of: a phenolic
hydroxyl group-containing aromatic hydrocarbon group (P), an alkoxy
group-containing condensed polycyclic aromatic hydrocarbon group
(B), and a divalent hydrocarbon group (X) selected from methylene,
an alkylidene group and an aromatic hydrocarbon
structure-containing methylene group, and the phenol resin has, in
a molecular structure, a structure in which the phenolic hydroxyl
group-containing aromatic hydrocarbon group (P) and the alkoxy
group-containing condensed polycyclic aromatic hydrocarbon group
(B) are bonded via the divalent hydrocarbon group (X) selected from
methylene, the alkylidene group and the aromatic hydrocarbon
structure-containing methylene group.
2. The epoxy resin composition according to claim 1, wherein the
phenol resin has, at a molecular end, a structural unit represented
by the following structural formula: B-X- [Chemical Formula 1]
wherein B is a structural unit of the alkoxy group-containing
condensed polycyclic aromatic hydrocarbon group (B), and X is a
structural unit of the divalent hydrocarbon group (X) selected from
methylene, the alkylidene group and the aromatic hydrocarbon
structure-containing methylene group.
3. The epoxy resin composition according to claim 1, wherein the
phenol resin has a melt viscosity at 150.degree. C., as measured by
an ICI viscometer in accordance with ASTM D4287, of 0.1 to 5.0
dPas.
4. The epoxy resin composition according to claim 1, wherein the
phenol resin contains a compound having a structure represented by
the following structural formula: P-X-B [Chemical Formula 2]
wherein P is a structural unit of the phenolic hydroxyl
group-containing aromatic hydrocarbon group (P), B is a structural
unit of the alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B) and X is a structural unit of the divalent
hydrocarbon group (X) selected from methylene, the alkylidene group
and the aromatic hydrocarbon structure-containing methylene group,
the content of the compound in the phenol resin being 1 to 30% by
mass.
5. The epoxy resin composition according to claim 1, wherein the
phenol resin is obtained by reacting a hydroxy group-containing
aromatic compound (a1), an alkoxy group-containing condensed
polycyclic aromatic compound (a2) and a carbonyl group-containing
compound (a3), and the content of a compound represented by the
following structural formula: B-X-B [Chemical Formula 3] wherein B
is a structural unit of the alkoxy group-containing condensed
polycyclic aromatic hydrocarbon group (B) and X is a structural
unit of the divalent hydrocarbon group (X) selected from methylene,
the alkylidene group and the aromatic hydrocarbon
structure-containing methylene group, in the phenol resin is 5% by
mass or less.
6. An epoxy resin cured article obtained by curing the epoxy resin
composition according to any one of claims 1 to 5.
7. A semiconductor encapsulation material comprising the epoxy
resin composition according to any one of claims 1 to 5 which
further contains, in addition to the epoxy resin and the curing
agent, an inorganic filler within a range of 70 to 95% by mass with
respect to the epoxy resin composition.
8. A novel phenol resin, including respective structural units of:
a phenolic hydroxyl group-containing aromatic hydrocarbon group
(P), an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B), and a divalent hydrocarbon group (X)
selected from methylene, an alkylidene group and an aromatic
hydrocarbon structure-containing methylene group, wherein the
phenol resin has, in a molecular structure, a structure in which
the phenolic hydroxyl group-containing aromatic hydrocarbon group
(P) and the alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B) are bonded via the divalent hydrocarbon group
(X) selected from methylene, the alkylidene group and the aromatic
hydrocarbon structure-containing methylene group, and the phenol
resin has a melt viscosity at 150.degree. C., as measured by an ICI
viscometer in accordance with ASTM D4287, of 0.1 to 5.0 dPas and a
hydroxyl group equivalent of 120 to 500 g/eq.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of application Ser. No.
11/817,535, filed Aug. 31, 2007, and wherein application Ser. No.
11/817,535 is a national stage application filed under 35 USC
.sctn.371 of International Application No. PCT/JP2006/303902, filed
Mar. 1, 2006, the entire contents of which are incorporated herein
by reference.
TECNICL FIELD
[0002] The present invention relates to an epoxy resin composition
which is excellent in heat resistance, dielectric characteristics
and curability during the curing reaction of the resulting cured
article and can be suited for use in applications such as
semiconductor encapsulation materials, printed circuit boards,
coating materials and castings, and to a cured article thereof, a
novel phenol resin and a novel epoxy resin.
BACKGROUND ART
[0003] An epoxy resin composition containing an epoxy resin and a
curing agent thereof as essential components are widely used in
electronic and electric components such as semiconductor
encapsulation materials and printed circuit boards, conductive
adhesives such as conductive pastes, other adhesives, matrixes for
composite materials, coating materials, photoresist materials and
developing materials because of excellent various physical
properties such as heat resistance, moisture resistance and low
viscosity.
[0004] In these various applications, particularly advanced
materials, it has recently been required to further improve
performances typified by heat resistance and moisture resistance.
For example, in the field of semiconductor encapsulation materials,
a reflow treatment temperature increased due to shift to surface
mounting packages such as BGA and CSP and correspondence to
lead-free solders, and thus electronic component encapsulation
resin materials having excellent moisture soldering resistance are
more required than before.
[0005] As the technique for producing electronic component
encapsulation resin materials which meet such requirements, for
example, there is known a technique in which fluidity is improved
by using, as a curing agent for epoxy resin, a methoxy
group-containing phenol resin obtained by methoxylating a phenolic
hydroxyl group in a resol resin and converting the methoxylated
resol resin into a novolak resin in the presence of an acid
catalyst and also proper flexibility is imparted to the cured
article, and thus moisture resistance and impact resistance of the
cured article itself are improved (see, for example, Japanese
Unexamined Patent Application, First Publication No.
2004-10700).
[0006] However, such a curing agent for epoxy resin is inferior in
heat resistance because of small number of functional groups per
molecule. In the field of electronic components, it is of urgent
necessity to develop a high-frequency device capable of coping with
higher frequency and materials having low dielectric constant and
low dielectric dissipation factor are required to electronic
component-related materials such as semiconductor encapsulation
materials. The cured article obtained by using the methoxy
group-containing phenol resin as the curing agent for epoxy resin
has less crosslink points and therefore dielectric characteristics
are improved to some extent, however, dielectric constant and
dielectric dissipation factor do not attain the level which has
recently been required.
[0007] As described above, in the field of electronic
component-related materials, there has never been obtained an epoxy
resin composition capable of coping with recent higher frequency
without causing deterioration of heat resistance.
DISCLOSURE OF THE INVENTION
[0008] Therefore, an object to be attained by the present invention
is to provide an epoxy resin composition capable of realizing low
dielectric constant and low dielectric dissipation factor, which is
suited for use as a latest high frequency type electronic
component-related material, without deteriorating heat resistance
during the curing reaction and a cured article thereof, a novel
epoxy resin which impart these performances, and a novel phenol
resin.
[0009] The present inventors have intensively studied so as to
attain the above object and found that the dielectric constant and
the dielectric dissipation factor can be remarkably decreased while
maintaining excellent heat resistance by introducing an
alkoxynaphthalene structure into a phenol novolak resin or novolak
type epoxy resin skeleton, and thus the present invention has been
completed.
[0010] The present invention relates to an epoxy resin composition
(hereinafter, this epoxy resin composition is abbreviated to "epoxy
resin composition (I)") including an epoxy resin and a curing agent
as essential components, wherein the curing agent is a phenol resin
which has the respective structural units of:
[0011] a phenolic hydroxyl group-containing aromatic hydrocarbon
group (P),
[0012] an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B), and
[0013] a divalent hydrocarbon group (X) selected from methylene, an
alkylidene group and an aromatic hydrocarbon structure-containing
methylene group, and the phenol resin has, in a molecular
structure, a structure in which the phenolic hydroxyl
group-containing aromatic hydrocarbon group (P) and the alkoxy
group-containing condensed polycyclic aromatic hydrocarbon group
(B) are bonded via the divalent hydrocarbon group (X) selected from
methylene, the alkylidene group and the aromatic hydrocarbon
structure-containing methylene group.
[0014] Also the present invention relates to an epoxy resin cured
article obtained by curing epoxy resin composition (I).
[0015] Also the present invention relates to a novel phenol resin,
including the respective structural units of:
[0016] a phenolic hydroxyl group-containing aromatic hydrocarbon
group (P),
[0017] an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B), and
[0018] a divalent hydrocarbon group (X) selected from methylene, an
alkylidene group and an aromatic hydrocarbon structure-containing
methylene group, wherein the phenol resin has, in a molecular
structure, a structure in which the phenolic hydroxyl
group-containing aromatic hydrocarbon group (P) and the alkoxy
group-containing condensed polycyclic aromatic hydrocarbon group
(B) are bonded via the divalent hydrocarbon group (X) selected from
methylene, the alkylidene group and the aromatic hydrocarbon
structure-containing methylene group, and the phenol resin has a
melt viscosity at 150.degree. C., as measured by an ICI viscometer,
of 0.1 to 5.0 dPas and a hydroxyl group equivalent of 120 to 500
g/eq.
[0019] Also the present invention relates to an epoxy resin
composition (hereinafter, this epoxy resin composition is
abbreviated to "epoxy resin composition (II)") including an epoxy
resin and a curing agent as essential components, wherein the epoxy
resin has the respective structural units of:
[0020] a glycidyloxy group-containing aromatic hydrocarbon group
(E),
[0021] an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B), and
[0022] a divalent hydrocarbon group (X) selected from methylene, an
alkylidene group and an aromatic hydrocarbon structure-containing
methylene, and the epoxy resin has, in a molecular structure, a
structure in which the glycidyloxy group-containing aromatic
hydrocarbon group (E) and the alkoxy group-containing condensed
polycyclic aromatic hydrocarbon group (B) are bonded via the
methylene group (X).
[0023] Also the present invention relates to a novel epoxy resin,
including the respective structural units of:
[0024] a glycidyloxy group-containing aromatic hydrocarbon group
(E),
[0025] an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B), and
[0026] a divalent hydrocarbon group (X) selected from methylene, an
alkylidene group and an aromatic hydrocarbon structure-containing
methylene group, wherein the epoxy resin has, in a molecular
structure, a structure in which the glycidyloxy group-containing
aromatic hydrocarbon group (E) and the alkoxy group-containing
condensed polycyclic aromatic hydrocarbon group (B) are bonded via
the methylene group (X), and the epoxy resin has a melt viscosity
at 150.degree. C., measured by an ICI viscometer, of 0.1 to 5.0
dPas and an epoxy group equivalent of 200 to 500 g/eq.
[0027] Also the present invention relates to a semiconductor
encapsulation material, including epoxy resin composition (I) or
(II) which further contains, in addition to the epoxy resin and the
curing agent, an inorganic filler within a range of 70 to 95% by
mass with respect to the epoxy resin composition.
[0028] According to the present invention, there can be provided an
epoxy resin composition capable of realizing low dielectric
constant and low dielectric dissipation factor, which is suited for
use as a latest high-frequency type electronic component-related
material, while maintaining excellent heat resistance of a cured
article and a cured article thereof, a novel phenol resin which
imparts these performances, and a novel epoxy resin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a graph showing a GPC chart of a phenol resin
obtained in Example 1.
[0030] FIG. 2 is a graph showing a .sup.13C-NMR spectrum of a
phenol resin obtained in Example 1.
[0031] FIG. 3 is a graph showing a mass spectrum of a phenol resin
obtained in Example 1.
[0032] FIG. 4 is a graph showing a GPC chart of a phenol resin
obtained in Example 2.
[0033] FIG. 5 is a graph showing a .sup.13C-NMR spectrum of a
phenol resin obtained in Example 2.
[0034] FIG. 6 is a graph showing a mass spectrum of a phenol resin
obtained in Example 2.
[0035] FIG. 7 is a graph showing a GPC chart of a phenol resin
obtained in Example 3.
[0036] FIG. 8 is a graph showing a GPC chart of a phenol resin
obtained in Example 4.
[0037] FIG. 9 is a graph showing a GPC chart of a phenol resin
obtained in Example 5.
[0038] FIG. 10 is a graph showing a GPC chart of a phenol resin
obtained in Example 6.
[0039] FIG. 11 is a graph showing a GPC chart of a phenol resin
obtained in Example 7.
[0040] FIG. 12 is a graph showing a GPC chart of a phenol resin
obtained in Example 8.
[0041] FIG. 13 is a graph showing a GPC chart of an epoxy resin
obtained in Example 9.
[0042] FIG. 14 is a graph showing a .sup.13C-NMR spectrum of an
epoxy resin obtained in Example 9.
[0043] FIG. 15 is a graph showing a mass spectrum of an epoxy resin
obtained in Example 9.
[0044] FIG. 16 is a graph showing a GPC chart of an epoxy resin
obtained in Example 10.
[0045] FIG. 17 is a graph showing a .sup.13C-NMR spectrum of an
epoxy resin obtained in Example 10.
[0046] FIG. 18 is a graph showing a mass spectrum of an epoxy resin
obtained in Example 10.
[0047] FIG. 19 is a graph showing a GPC chart of an epoxy resin
obtained in Example 12.
BEST MODE FOR CARRYING OUT THE INVENTION
[0048] The present invention will now be described in detail.
[0049] Epoxy resin composition (I) of the present invention
includes an epoxy resin and a curing agent as essential components,
wherein the curing agent is a phenol resin which has the respective
structural units of a phenolic hydroxyl group-containing aromatic
hydrocarbon group (P), an alkoxy group-containing condensed
polycyclic aromatic hydrocarbon group (B), and a divalent
hydrocarbon group (X) selected from methylene, an alkylidene group
and an aromatic hydrocarbon structure-containing methylene group,
and which also has, in a molecular structure, a structure in which
the phenolic hydroxyl group-containing aromatic hydrocarbon group
(P) and the alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B) are bonded via the divalent hydrocarbon group
(X) selected from methylene, the alkylidene group and the aromatic
hydrocarbon structure-containing methylene group.
[0050] That is, the phenol resin essentially includes a structural
site represented by the following structural site A1:
[Chemical Formula 1]
-P-X-B- A1
wherein P is a structural unit of the phenolic hydroxyl
group-containing aromatic hydrocarbon group (P), B is a structural
unit of the alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B) and X is a structural unit of the divalent
hydrocarbon group (X) (hereinafter each group is abbreviated to
"methylene group (X)" or the like) selected from methylene, the
alkylidene group and the aromatic hydrocarbon structure-containing
methylene group, in a molecular structure.
[0051] In the present invention, because of such characteristic
chemical structures, an aromatic content in the molecular structure
increases, and excellent heat resistance is exhibited. Since a
crosslink point in a cured article exists in the vicinity of an
alkoxy group-containing condensed polycyclic aromatic hydrocarbon
group (B), it is possible to reduce an adverse influence such as
decrease in the dielectric constant and dielectric dissipation
factor caused by a secondary hydroxyl group produced during curing,
and thus excellent dielectric characteristics can be exhibited. It
is worthy of special mention to exhibit excellent dielectric
characteristics while introducing a functional group having
comparatively high polarity such as alkoxy group.
[0052] The phenolic hydroxyl group-containing aromatic hydrocarbon
group (P) can have various structures, and is preferably a phenol
or naphthol represented by any one of the following structural
formulas P1 to P16, or an aromatic hydrocarbon group formed from
the phenol or the naphthol thereof, having an alkyl group as a
substituent on the aromatic ring because of excellent dielectric
performances.
##STR00001## ##STR00002##
[0053] When each of these structures is located at the molecular
end, a monovalent aromatic hydrocarbon group is formed. Regarding
those having at least two bonding sites with the other structural
site on the naphthalene skeleton among these structures, these
bonding sites may exist on the same or different nucleus.
[0054] Among the phenolic hydroxyl group-containing aromatic
hydrocarbon groups (P) described above in detail, those having a
methyl group as a substituent on the aromatic ring can impart
excellent flame retardancy to an epoxy resin cured article itself,
and it becomes possible to design a halogen-free material which has
highly been required in the field of electronic components,
recently.
[0055] Furthermore, the phenolic hydroxyl group-containing aromatic
hydrocarbon groups (P) having a methyl group at the ortho-position
of the phenol skeleton typified by those represented by the
structural formulas P6, P7, P8 and P9 are preferable because a
remarkable effect of improving heat resistance and dielectric
characteristics of the cured article is exerted.
[0056] The alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B) contained in the phenol resin structure is a
monovalent or polyvalent aromatic hydrocarbon group having an
alkoxy group as a substituent on the condensed polycyclic aromatic
ring, and specific examples include alkoxynaphthalene type
structures represented by the following structural formulas B1 to
B15, or alkoxyanthracene represented by the following structural
formula B16.
##STR00003## ##STR00004##
[0057] When each structure is located at the molecular end, a
monovalent aromatic hydrocarbon group is formed. Among the
structures described above, the bonding site of those having at
least two bonding sites with the other structural site on the
naphthalene skeleton may exist on the same or different
nucleus.
[0058] Among the alkoxy group-containing condensed polycyclic
aromatic hydrocarbon groups (B) described above in detail, those
having an alkoxynaphthalene type structure are preferable because
the epoxy resin cured article is excellent in heat resistance.
Aromatic hydrocarbon groups formed from naphthalene structures
having a methoxy group or an ethoxy group as a substituent typified
by those represented by the structural formulas B1 to B13, and a
structure further having a methyl group as a substituent are
preferable because the epoxy resin cured article is excellent in
flame retardancy and it becomes possible to design a halogen-free
material which has highly been required in the field of electronic
components, recently.
[0059] Examples of the divalent hydrocarbon group (X) selected from
methylene, alkylidene group and aromatic hydrocarbon
structure-containing methylene group contained in the phenol resin
structure include, in addition to methylene, alkylidene group such
as ethylidene group, 1,1-propylidene group, 2,2-propylidene group,
dimethylene group, propane-1,1,3,3-tetrayl group,
n-butane-1,1,4,4-tetrayl group or n-pentane-1,1,5,5-tetrayl group.
Examples of the aromatic hydrocarbon structure-containing methylene
group include those having structures represented by the following
formulas X1 to X9.
##STR00005##
[0060] Among these groups, methylene is particularly preferable
because of excellent dielectric effect.
[0061] The phenol resin used in the present invention can employ
any combination of the structures shown in the respective specific
examples of the structural sites (P), (B) and (X). As described
above, the molecular structure of the phenol resin composed of each
structural site has essentially a structural site represented by
the following structural site A1:
[Chemical Formula 5]
-P-X-B- A1
wherein P is a structural unit of the phenolic hydroxyl
group-containing aromatic hydrocarbon group (P), B is a structural
unit of the alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B) and X is a structural unit of the methylene
group (X) in a molecular structure. Further specific examples
thereof include structures represented by the following structural
formulas A2 and A3,
[Chemical Formula 6]
P-X-B-X-P A2
B-X-P-X-P-X-B A3
; structures having, at the molecular end of a novolak structure
including, as a repeating unit, a structure represented by the
following structural formula A4 or A5:
##STR00006##
, a structure represented by the following structural formula
A6:
[Chemical Formula 8]
B-X- A6
; or alternating copolymer structures including, as a repeating
unit, structures represented by the following structural formulas
A7 to A10:
##STR00007##
[0062] In the present invention, the phenol resin can have various
structures, as described above, and the dielectric dissipation
factor of the epoxy resin cured article can be remarkably decreased
by having a structure represented by the above structural formula
A6 at the molecular end. Therefore, a phenol resin having a
structure of the structural formula A3, or a phenol resin including
a repeating unit of the formula A4 or A7 and a structure
represented by the structural formula A6 at the molecular end is
preferable. A phenol resin having a structure of the structural
formula A3 or a phenol resin including a repeating unit of the
formula A4 and a structure represented by the structural formula A6
at the molecular end is particularly preferable because the effect
of the present invention is remarkably excellent.
[0063] As described hereinafter, the phenol resin can be obtained
by reacting a hydroxy group-containing aromatic compound (a1), an
alkoxy group-containing aromatic compound (a2) and a carbonyl
group-containing compound (a3) and, in addition to the above
compounds of various structures, a compound represented by the
following structural formula:
P-X-B [Chemical Formula 10]
wherein P is a structural unit of a phenolic hydroxyl
group-containing aromatic hydrocarbon group (P), B is a structural
unit of an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B) and X is a structural unit of a methylene
group (X) is simultaneously produced and is contained in the phenol
resin. In the present invention, it is preferred that the content
of the compound is comparatively high, because melt viscosity of
the phenol resin itself can be decreased and the resulting epoxy
resin cured article is excellent in dielectric characteristics.
Specifically, the content of the component is preferably within a
range from 1 to 30% by mass based on the phenol resin. The content
of the compound is preferably within a range from 3 to 25% by mass,
and particularly preferably from 3 to 15% by mass, because such an
effect is remarkably exerted.
[0064] Similarly, as a result of the reaction of the hydroxy
group-containing aromatic compound (a1), the alkoxy
group-containing condensed polycyclic aromatic compound (a2) and
the carbonyl group-containing compound (a3), the phenol resin as
the product sometimes contain a compound having a structure
represented by the following structural formula
B-X-B [Chemical Formula 10]
wherein B is a structural unit of an alkoxy group-containing
condensed polycyclic aromatic hydrocarbon group (B) and X is a
structural unit of a methylene group (X). In the present invention,
in view of heat resistance of the epoxy resin cured article, the
content of the compound is preferably as small as possible, and it
is more preferable that the phenol resin does not contain any
compound. Therefore, the content of the compound in the phenol
resin is preferably 5% by mass or less, more preferably 3% by mass
or less, and particularly preferably 2% by mass or less.
[0065] The phenol resin preferably has a melt viscosity at
150.degree. C., as measured by an ICI viscometer, within a range
from 0.1 to 5.0 dPas because fluidity during molding and heat
resistance of the cured article are excellent. Furthermore, the
phenol resin more preferably has a hydroxyl group equivalent within
a range from 120 to 500 g/eq. because flame retardancy and
dielectric characteristics of the cured article are more improved.
In the present invention, those having the hydroxyl group
equivalent and melt viscosity within such a range are employed as
the novel phenol resin of the present invention. When the hydroxyl
group equivalent is within a range from 200 to 350 g/eq., balance
between dielectric characteristics of the cured article and
curability of the composition is particularly excellent.
[0066] In the phenol resin, a molar ratio of the phenolic hydroxyl
group-containing aromatic hydrocarbon group (P) to the alkoxy
group-containing condensed polycyclic aromatic hydrocarbon group
(B), the former/the latter, is preferably within a range from 30/70
to 98/2 because flame retardancy and dielectric characteristics of
the cured article are more improved.
[0067] The phenol resin can be produced by the method described
below in detail. The method for producing a phenol resin will be
described in detail.
[0068] The phenol resin can be produced by reacting a hydroxy
group-containing aromatic compound (a1), an alkoxy group-containing
aromatic compound (a2) and a carbonyl group-containing compound
(a3).
[0069] It is worthy of special mention that the reaction proceeds
without causing any hydrolysis, although the alkoxy
group-containing aromatic compound (a2) is used as a raw material.
An alkoxy group obtained by alkoxylating a phenolic hydroxyl group
is widely used in a technique of protecting a phenolic hydroxyl
group and is easily hydrolyzed in a strong acidic environment,
while an alkoxy group can be introduced into a phenol resin
structure without causing any hydrolysis in the present
invention.
[0070] Specific examples of the hydroxy group-containing aromatic
compound (a1) used in the above method for producing include
unsubstituted phenols such as phenol, resorcinol and hydroquinone;
monosubstituted phenols such as cresol, phenylphenol, ethylphenol,
n-propylphenol, iso-propylphenol and t-butylphenol; disubstituted
phenols such as xylenol, methylpropylphenol, methylbutylphenol,
methylhexylphenol, dipropylphenol and dibutylphenol; trisubstituted
phenols such as mesitol, 2,3,5-trimethylphenol and
2,3,6-trimethylphenol; and naphthols such as 1-naphthol, 2-naphthol
and methylnaphthol.
[0071] These compounds may be used in combination.
[0072] Among these compounds, as described above, 1-naphthol,
2-naphthol, cresol and phenol are particularly preferable in view
of dielectric characteristics and flame retardancy of the cured
article.
[0073] Specific examples of the alkoxy group-containing aromatic
compound (a2) include 1-methoxynaphthalene, 2-methoxynaphthalene,
1-methyl-2-methoxynaphthalene, 1-methoxy-2-methylnaphthalene,
1,3,5-trimethyl-2-methoxynaphthalene, 2,6-dimethoxynaphthalene,
2,7-dimethoxynaphthalene, 1-ethoxynaphthalene,
1,4-dimethoxynaphthalene, 1-t-butoxynaphthalene and
1-methoxyanthracene.
[0074] Among these compounds, 2-methoxynaphthalene and
2,7-dimethoxynaphthalene are particularly preferable because an
alkoxynaphthalene skeleton is easily formed at the molecular end,
and 2-methoxynaphthalene is particularly preferable in view of
dielectric characteristics.
[0075] Specific examples of the carbonyl group-containing compound
(a3) include aliphatic aldehydes such as formaldehyde, acetaldehyde
and propionaldehyde; dialdehydes such as glyoxal; aromatic
aldehydes such as benzaldehyde, 4-methylbenzaldehyde,
3,4-dimethylbenzaldehyde, 4-biphenylaldehyde and naphthylaldehyde;
and ketone compounds such as benzophenone, fluorenone and
indanone.
[0076] Among these compounds, formaldehyde, benzaldehyde,
4-biphenylaldehyde and naphthylaldehyde are preferable because the
resulting cured article is excellent in flame retardancy, and
formaldehyde is particularly preferable because of excellent
dielectric characteristics.
[0077] Examples of the method of reacting the hydroxy
group-containing aromatic compound (a1), the alkoxy
group-containing condensed polycyclic aromatic compound (a2) and
the carbonyl group-containing compound (a3) include:
1) a method of charging a hydroxy group-containing aromatic
compound (a1), an alkoxy group-containing condensed polycyclic
aromatic compound (a2) and a carbonyl group-containing compound
(a3), substantially simultaneously, and reacting them while
stirring with heating in the presence of a proper polymerization
catalyst, 2) a method of reacting 1 mol of an alkoxy
group-containing condensed polycyclic aromatic compound (a2) with
0.05 to 30 mols, preferably 2 to 30 mols of a carbonyl
group-containing compound (a3), charging a hydroxy group-containing
aromatic compound (a1) and reacting with the reaction product, and
3) a method of previously mixing a hydroxy group-containing
aromatic compound (a1) with an alkoxy group-containing condensed
polycyclic aromatic compound (a2), continuously or intermittently
adding a carbonyl group-containing compound (a3) in the system, and
reacting with the reaction product. As used herein, substantially
simultaneously means that all materials are charged until the
reaction is accelerated by heating.
[0078] Among these methods, the methods 1) and 3) are preferable
because it is possible to control the content of a compound having
a structure represented by the following structural formula:
P-X-B [Chemical Formula 12]
and to satisfactorily suppress the production of a compound having
a structure represented by the following structural formula:
B-X-B [Chemical Formula 13]
[0079] The polymerization catalyst used herein is not specifically
limited and an acid catalyst is preferable, and examples thereof
include inorganic acids such as hydrochloric acid, sulfuric acid
and phosphoric acid; organic acids such as methanesulfonic acid,
p-toluenesulfonic acid and oxalic acid; and Lewis acids such as
boron trifluoride, anhydrous aluminum chloride and zinc chloride.
The content of the polymerization catalyst is preferably within a
range from 0.1 to 5% by mass based on the total mass of the
materials to be charged.
[0080] A ratio of the hydroxy group-containing aromatic compound
(a1), the alkoxy group-containing condensed polycyclic aromatic
compound (a2) and the carbonyl group-containing compound (a3) to be
charged in the reaction is not specifically limited. A molar ratio
of the hydroxy group-containing aromatic compound (a1) to the
alkoxy group-containing aromatic compound (a2), (a1)/(a2), is
preferably within a range from 30/70 to 98/2 and a ratio of the
total number of mols of the hydroxy group-containing aromatic
compound (a1) and the alkoxy group-containing condensed polycyclic
aromatic compound (a2) to the number of mols of the carbonyl
group-containing compound (a3), {(a1)+(a2)}/(a3), is preferably
within a range from 51/49 to 97/3.
[0081] To control the content of the compound having a structure
represented by the following structural formula:
P-X-B [Chemical Formula 14]
and the content of the compound having a structure represented by
the following structural formula:
B-X-B [Chemical Formula 15]
in the phenol resin produced by the method 1) or 3), the molar
ratio (a1)/(a2) is preferably 2 or more and the ratio
{(a1)+(a2)}/(a3) is preferably within a range from 51/49 to
97/3.
[0082] When this reaction is conducted, an organic solvent can be
used, if necessary. Examples of the usable organic solvent include,
but are not limited to, methyl cellosolve, ethyl cellosolve,
toluene, xylene and methyl isobutyl ketone. The content of the
organic solvent is usually within a range from 10 to 500% by mass,
and preferably from 30 to 250% by mass, based on the total mass of
the materials to be charged. The reaction temperature is preferably
within a range from 40 to 250.degree. C., and more preferably from
100 to 200.degree. C. The reaction time is usually within a range
from 1 to 10 hours.
[0083] When the resulting polyvalent hydroxy compound shows high
degree of coloration, antioxidants and reducing agents may be added
so as to suppress coloration. Examples of the antioxidant include,
but are not limited to, hindered phenolic compounds such as
2,6-dialkylphenol derivative; divalent sulfur-based compounds; and
phosphite ester-based compounds containing a trivalent phosphorus
atom. Examples of the reducing agent include, but are not limited
to, hypophosphorous acid, phosphorous acid, thiosulfuric acid,
sulfurous acid, hydrosulfite, or salts thereof and zinc.
[0084] After the completion of the reaction, the reaction mixture
is subjected to neutralization or washing treatment until the pH
value of the reaction mixture becomes the value within a range from
3 to 7, and preferably from 4 to 7. The neutralization or washing
treatment may be conducted by a conventional method. For example,
when an acid catalyst is used, basic substances such as sodium
hydroxide, potassium hydroxide, sodium carbonate, ammonia,
triethylenetetramine and aniline can be used as a neutralizer. In
case of neutralization, buffers such as phosphoric acid may be
previously mixed. Alternatively, the pH value may be adjusted to
the value within a range from 3 to 7 with oxalic acid or the like
after the pH is adjusted to the basic side. After subjecting to the
neutralization or washing treatment, the unreacted material
containing mainly the hydroxy group-containing aromatic compound
(a1) and the alkoxy group-containing aromatic compound (a2), the
organic solvent and by-product are distilled off while heating
under reduced pressure and then the product is concentrated, and
thus the objective polyvalent hydroxy compound can be obtained. The
unreacted material thus recovered can be reused. After the
completion of the reaction, when a precise filtration step is
introduced into the treating operation, inorganic salts and foreign
matters can be removed by purification, and therefore this method
is preferable.
[0085] In epoxy resin composition (I) of the present invention, the
phenol resin may be used alone, or used in combination with the
other curing agent as far as the effects of the present invention
are not adversely affected. Specifically, the other curing agent
can be used in combination so that the content of the phenol resin
is 30% by mass or more, and preferably 40% by mass or more, based
on the total mass of the curing agent.
[0086] Examples of the other curing agent which can used in
combination with the phenol resin of the present invention include,
but are not limited to, amine-based compounds, amide-based
compounds, acid anhydride-based compounds, phenolic compounds other
than the above phenol resins, and polyvalent phenol compounds of
aminotriazine-modified phenol resins (polyvalent phenol compounds
in which phenol nuclei are connected with melamine or
benzoguanamine).
[0087] Among these, phenol novolak resin, cresol novolak resin,
aromatic hydrocarbon formaldehyde resin-modified phenol resin,
phenol aralkyl resin, naphthol alaralkyl resin, naphthol novolak
resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol
co-condensed novolak resin, biphenyl-modified phenol resin,
biphenyl-modified naphthol resin and aminotriazine-modified phenol
resin are preferable because of excellent flame retardancy, and
compounds, for example, phenol resins having high aromatic
properties and high hydroxyl group equivalent such as phenol
aralkyl resin, naphthol aralkyl resin, biphenyl-modified phenol
resin and biphenyl-modified naphthol resin, and
aminotriazine-modified phenol resins having a nitrogen atom are
used particularly preferably because the resulting cured article is
excellent in flame retardancy and dielectric characteristics.
[0088] Examples of the epoxy resin (B) used in epoxy resin
composition (I) of the present invention include bisphenol A type
epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy
resin, tetramethylbiphenyl type epoxy resin, phenol novolak type
epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak
type epoxy resin, triphenylmethane type epoxy resin,
tetraphenylethane type epoxy resin, dicyclopentadiene-phenol
addition reaction type epoxy resin, phenol aralkyl type epoxy
resin, naphthol novolak type epoxy resin, naphtholaralkyl type
epoxy resin, naphthol-phenol co-condensed novolak type epoxy resin,
naphthol-cresol co-condensed novolak type epoxy resin, aromatic
hydrocarbon formaldehyde resin-modified phenol resin type epoxy
resin and biphenyl novolak type epoxy resin. These epoxy resins may
be used alone or in combination.
[0089] Among these epoxy resins, biphenyl type epoxy resin,
naphthalene type epoxy resin, phenol aralkyl type epoxy resin,
biphenyl novolak type epoxy resin and xanthene type epoxy resin are
particularly preferable because of excellent flame retardancy and
dielectric characteristics.
[0090] The contents of the epoxy resin (B) and the curing agent in
epoxy resin composition (I) of the present invention are not
specifically limited. The content of an active group in the curing
agent containing the phenol resin (A) is preferably within a range
from 0.7 to 1.5 equivalents based on 1 equivalent of the total of
epoxy groups of the epoxy resin (B) because the resulting cured
article is excellent in characteristics.
[0091] If necessary, curing accelerators can also be added to epoxy
resin composition (I) of the present invention. Various curing
accelerators can be used and examples thereof include
phosphorous-based compound, tertiaryamine, imidazole, organic acid
metal salt, Lewis acid and amine complex salt. When used as
semiconductor encapsulation materials, triphenylphosphine is
preferable in case of a phosphorous-based compound and
1,8-diazabicyclo-[5.4.0]-undecene (DBU) is preferable in case of a
tertiary amine because of excellent curability, heat resistance,
electrical characteristics and moisture resistant reliability.
[0092] Another epoxy resin composition (II) of the present
invention is an epoxy resin composition including an epoxy resin
and a curing agent as essential components, wherein the epoxy resin
has the respective structural units of:
[0093] a glycidyloxy group-containing aromatic hydrocarbon group
(E),
[0094] an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B), and
[0095] a divalent hydrocarbon group (X) selected from methylene, an
alkylidene group and an aromatic hydrocarbon structure-containing
methylene group, and also has, in a molecular structure, a
structure in which the glycidyloxy group-containing aromatic
hydrocarbon group (E) and the alkoxy group-containing condensed
polycyclic aromatic hydrocarbon group (B) are bonded via the
divalent hydrocarbon group (X) selected from methylene, the
alkylidene group and the aromatic hydrocarbon structure-containing
methylene group.
[0096] That is, the epoxy resin in epoxy resin composition (II) is
obtained by reacting a phenol resin constituting epoxy resin
composition (I) with epihalohydrin, thereby epoxidating the phenol
resin, and has a basic skeleton common to the phenol resin.
Therefore, similar to the case of the phenol resin, the aromatic
content in the molecular structure increases and excellent heat
resistance is imparted to the cured article and also the
concentration of the epoxy group can be appropriately decreased and
the alkoxy group is contained in the molecular structure, and thus
the dielectric constant and dielectric dissipation factor of the
cured article can be decreased.
[0097] Similar to the phenol resin, the epoxy resin essentially
contains, in a molecular structure, a structural site represented
by the following structural site Y1:
[Chemical Formula 16]
-E-X-B- Y1
wherein E is a structural unit of the glycidyloxy group-containing
aromatic hydrocarbon group (E), B is a structural unit of the
alkoxy group-containing condensed polycyclic aromatic hydrocarbon
group (B) and X is a structural unit of the methylene group
(X).
[0098] In the present invention, because of a characteristic
chemical structure, an aromatic content in the molecular structure
increases and excellent heat resistance is exhibited. Since a
crosslink point in a cured article exists in the vicinity of an
alkoxy group-containing condensed polycyclic aromatic hydrocarbon
group (B), it is possible to reduce an adverse influence such as
decrease in the dielectric constant and dielectric dissipation
factor caused by a secondary hydroxyl group produced during curing,
and thus excellent dielectric characteristics can be exhibited. It
is worthy of special mention to exhibit excellent dielectric
characteristics while introducing a functional group having
comparatively high polarity such as alkoxy group.
[0099] The glycidyloxy group-containing aromatic hydrocarbon group
(E) is not specifically limited and preferred examples thereof
include aromatic hydrocarbon groups represented by the following
structural formulas E1 to E16 because of excellent dielectric
performances.
##STR00008## ##STR00009## ##STR00010## ##STR00011##
[0100] When each structure is located at the molecular end, a
monovalent aromatic hydrocarbon group is formed. Among the
structures described above, the bonding site of those having at
least two bonding sites with the other structural site on the
naphthalene skeleton may exist on the same or different
nucleus.
[0101] Among the glycidyloxy group-containing aromatic hydrocarbon
groups (E) described above in detail, those having a methyl group
as a substituent on the aromatic ring can impart excellent flame
retardancy to an epoxy resin cured article itself and it becomes
possible to design a halogen-free material which has highly been
required in the field of electronic components, recently.
[0102] Furthermore, the glycidyloxy group-containing aromatic
hydrocarbon groups (E) having a methyl group at the ortho-position
of the phenol skeleton typified by those represented by the
structural formulas E6, E7, E8 and E9 are preferable because a
remarkable effect of improving heat resistance and dielectric
characteristics of the cured article is exerted.
[0103] The alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group (B) contained in the epoxy resin structure is
specifically the same as that in the phenol resin of the above
epoxy resin composition (I).
[0104] The methylene group (X) contained in the epoxy resin
structure is specifically the same as that in the phenol resin of
the above epoxy resin composition (I).
[0105] The epoxy resin used in the present invention can employ any
combination of the structures shown in the respective specific
examples of the structural sites (E), (B) and (X). As described
above, the molecular structure of the phenol resin composed of each
structural site has essentially a structural site represented by
the following structural site Y1:
[Chemical Formula 18]
-E-X-B- Y1
wherein E is a structural unit of the glycidyloxy group-containing
aromatic hydrocarbon group (E), B is a structural unit of the
alkoxy group-containing condensed polycyclic aromatic hydrocarbon
group (B) and X is a structural unit of the methylene group (X) in
a molecular structure. Specific examples thereof include structures
represented by the following structural formulas Y2 and Y3,
[Chemical Formula 19]
E-X-B-X-E Y2
B-X-E-X-E-X-B Y3
; structures having, at the molecular end of a novolak structure
including, as a repeating unit, a structure represented by the
following structural formula Y4 or Y5:
##STR00012##
, a structure represented by the following structural formula
A6:
[Chemical Formula 21]
B-X- A6
; and alternating copolymer structure including, as a repeating
unit, structures represented by the following structural formulas
Y7 to Y10:
##STR00013##
[0106] In the present invention, the epoxy resin can have various
structures, as described above, and the dielectric dissipation
factor of the epoxy resin cured article can be remarkably decreased
by having a structure represented by the above structural formula
A6 at the molecular end. Therefore, an epoxy resin having a
structure of the structural formula Y3, or a phenol resin including
a repeating unit of the formula Y4 or Y7 and a structure
represented by the structural formula A6 at the molecular end is
preferable. An epoxy resin having a structure of the structural
formula Y3 or an epoxy resin including a repeating unit of the
formula Y4 and a structure represented by the structural formula A6
at the molecular end is particularly preferable because the effect
of the present invention is remarkably excellent.
[0107] As described hereinafter, the epoxy resin can be produced by
reacting a hydroxy group-containing aromatic compound (a1), an
alkoxy group-containing aromatic compound (a2) and a carbonyl
group-containing compound (a3) and reacting the reaction product
with epihalohydrin. In this case, since compounds of various
structures are produced in the production of the phenol resin as a
precursor of the epoxy resin, finally obtained epoxy resin contain
compounds of various structures. In the present invention, a
compound represented by the following structural formula:
E-X-B [Chemical Formula 23]
wherein E is a structural unit of a glycidyloxy group-containing
aromatic hydrocarbon group (E), B is a structural unit of an alkoxy
group-containing condensed polycyclic aromatic hydrocarbon group
(B) and X is a structural unit of a methylene group (X) is
simultaneously produced and is contained in the epoxy resin.
[0108] Similar to the above phenol resin, it is preferred that the
content of the compound is comparatively high in view of melt
viscosity and dielectric characteristics. The content of the
compound is preferably within a range from 1 to 30% by mass, more
preferably from 3 to 25% by mass, and particularly preferably from
3 to 15% by mass, based on the resin.
[0109] Similarly, since the epoxy resin is produced by reacting the
hydroxy group-containing aromatic compound (a1), the alkoxy
group-containing condensed polycyclic aromatic compound (a2) and
the carbonyl group-containing compound (a3), the epoxy resin as the
product sometimes contain a compound having a structure represented
by the following structural formula:
B-X-B [Chemical Formula 24]
wherein B is a structural unit of an alkoxy group-containing
condensed polycyclic aromatic hydrocarbon group (B) and X is a
structural unit of a methylene group (X). In view of heat
resistance of the epoxy resin cured article, the content of the
compound is preferably as small as possible and it is more
preferable that the epoxy resin does not contain any compound.
Therefore, the content of the compound in the epoxy resin is
preferably 5% by mass or less, more preferably 3% by mass or less,
and particularly preferably 2% by mass or less.
[0110] The epoxy resin preferably has an epoxy group equivalent
within a range from 200 to 500 g/eq. because flame retardancy and
dielectric characteristics of the cured article are more improved.
Furthermore, the epoxy resin preferably has a melt viscosity at
150.degree. C., as measured by an ICI viscometer, within a range
from 0.1 to 5.0 dPas because fluidity during molding and heat
resistance of the cured article are excellent. In the present
invention, those having the epoxy group equivalent and melt
viscosity within such a range are employed as a novel epoxy resin
of the present invention. When the epoxy group equivalent is within
a range from 260 to 420 g/eq., balance between dielectric
characteristics of the cured article and curability of the
composition is particularly excellent.
[0111] In the epoxy resin, a ratio of the glycidyloxy
group-containing aromatic hydrocarbon group (E) to the alkoxy
group-containing condensed polycyclic aromatic hydrocarbon group
(B), the former/the latter, is preferably within a range from 30/70
to 98/2 because flame retardancy and dielectric characteristics of
the cured article are more improved.
[0112] The epoxy resin can be produced by the method described
below in detail.
[0113] Specifically, the objective epoxy resin can be produced by
producing a phenol resin in epoxy resin composition (I) by the
above method and reacting the phenol resin with epihalohydrin. For
example, there can be employed a method of adding 2 to 10 mols of
epihalohydrin to 1 mol of a phenolic hydroxyl group in the phenol
resin and reacting at a temperature of 20 to 120.degree. C. for 0.5
to 10 hours while simultaneously or gradually adding 0.9 to 2.0
mols of a basic catalyst to 1 mol of a phenolic hydroxyl group.
This basic catalyst may be used in the form of a solid or an
aqueous solution. When using the aqueous solution, there can be
used a method of continuously adding the aqueous solution,
continuously distilling off water and epihalohydrins from the
reaction mixture under reduced pressure or normal pressure,
separating them, removing water and continuously returning
epihalohydrins into the reaction mixture.
[0114] In case of industrial production, entire epihalohydrins used
in an initial batch for production of the epoxy resin are new
epihalohydrins. However, it is preferred to use epihalohydrin
recovered from the crude reaction product in combination with new
epihalohydrins corresponding the epihalohydrins consumed during the
reaction in the following batches. At this time, the epihalohydrin
to be used is not specifically limited and examples thereof include
epichlorohydrin, epibromohydrin and .beta.-methylepichlorohydrin.
Among these epihalohydrins, epichlorohydrin is preferable because
it is available with ease.
[0115] Specific examples of the basic catalyst include alkali earth
metal hydroxide, alkali metal carbonic acid salt and alkali metal
hydroxide. In view of excellent catalytic activity of the reaction
for synthesis of an epoxy resin, alkali metal hydroxide is
preferable and examples thereof include sodium hydroxide and
potassium hydroxide. These basic catalysts may be used in the form
of an aqueous solution having a concentration of about 10 to 55% by
mass or a solid. The reaction rate in the synthesis of an epoxy
resin can be increased by using in combination with an organic
solvent. Examples of the organic solvent include, but are not
limited to, ketones such as acetone and methyl ethyl ketone;
alcohols such as methanol, ethanol, 1-propyl alcohol, isopropyl
alcohol, 1-butanol, secondary butanol and tertiary butanol;
cellosolves such as methyl cellosolve and ethyl cellosolve; ethers
such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxane and
diethoxyethane; and aprotic polar solvents such as acetonitrile,
dimethyl sulfoxide and dimethyl formamide. These organic solvent
may be used alone, or may be used in combination so as to adjust
polarity.
[0116] The reaction product of the above epoxydation reaction is
washed with water and then the unreacted epihalohydrin and the
organic solvent used in combination are distilled off by
distillation with heating under reduced pressure. To obtain an
epoxy resin containing a small amount of a hydrolyzable halogen,
the resulting epoxy resin is dissolved in an organic solvent such
as toluene, methyl isobutyl ketone or methyl ethyl ketone and an
aqueous solution of an alkali metal hydroxide such as sodium
hydroxide or potassium hydroxide is added and then the reaction can
be further conducted. For the purpose of improving the reaction
rate, the reaction can be conducted in the presence of a phase
transfer catalyst such as quaternary ammonium salt or crown ether.
In case of using the phase transfer catalyst, the amount is
preferably within a range from 0.1 to 3.0% by mass based on the
amount of the epoxy resin to be used. After the completion of the
reaction, the resulting salt is removed by filtration or washing
with water, and then the solvent such as toluene or methyl isobutyl
ketone is distilled off with heating under reduce pressure to
obtain a high-purity epoxy resin.
[0117] In epoxy resin composition of the present invention (II),
the epoxy resin (A) obtained by the method of the present invention
can be used alone or in combination with the other epoxy resin as
far as the effects of the present invention are not adversely
affected. When using in combination, the content of the epoxy resin
of the present invention is preferably 30% by mass or more, and
particularly preferably 40% by mass or more, based on the entire
epoxy resin.
[0118] As the epoxy resin, which can be used in combination with
the epoxy resin of the present invention, various epoxy resins can
be used. Examples thereof include bisphenol A type epoxy resin,
bisphenol F type epoxy resin, biphenyl type epoxy resin,
tetramethylbiphenyl type epoxy resin, phenol novolak type epoxy
resin, cresol novolak type epoxy resin, bisphenol A novolak type
epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane
type epoxy resin, dicyclopentadiene-phenol addition reaction type
epoxy resin, phenol aralkyl type epoxy resin, naphthol novolak type
epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol
co-condensed novolak type epoxy resin, naphthol-cresol co-condensed
novolak type epoxy resin, aromatic hydrocarbon formaldehyde
resin-modified phenol resin type epoxy resin and biphenyl novolak
type epoxy resin. Among these epoxy resins, a phenol aralkyl type
epoxy resin, a biphenyl novolak type epoxy resin, a naphthol
novolak type epoxy resin containing a naphthalene skeleton, a
naphthol aralkyl type epoxy resin, a naphthol-phenol co-condensed
novolak type epoxy resin, a naphthol-cresol co-condensed novolak
type epoxy resin, a crystalline biphenyl type epoxy resin, a
tetramethyl biphenyl type epoxy resin, and a xanthene type epoxy
resin represented by the following structural formula:
##STR00014##
are particularly preferable because a cured article having
excellent flame retardancy and dielectric characteristics can be
obtained.
[0119] As the curing agent used in epoxy resin composition of the
present invention (II), known various curing agents for epoxy resin
such as amine-based compounds, amide-based compounds, acid
anhydride-based compounds and phenolic compounds can be used.
Specific examples of the amine-based compound include
diaminodiphenylmethane, diethylenetriamine, triethylenetetramine,
diaminodiphenylsulfon, isophoronediamine, imidazol, BF.sub.3-amine
complex and guanidine derivative; specific examples of the
amide-based compound include dicyandiamide, and polyamide resin
synthesized from a dimer of linolenic acid and ethylenediamine;
specific examples of the acid anhydride-based compound include
phthalic anhydride, trimellitic anhydride, pyromellitic anhydride,
maleic anhydride, tetrahydrophthalic anhydride,
methyltetrahydrophthalic anhydride, methylnadic anhydride,
hexahydrophthalic anhydride and methylhexahydrophthalic anhydride;
and specific examples of the phenol-based compound include
polyvalent phenol compounds such as phenol novolak resin, cresol
novolak resin, aromatic hydrocarbon formaldehyde resin-modified
phenol resin, dicyclopentadienephenol addition type resin, phenol
aralkyl resin (popular name, xylok resin), naphthol aralkyl resin,
trimethylolmethane resin, tetraphenylolethane resin, naphthol
novolak resin, naphthol-phenol co-condensed novolak resin,
naphthol-cresol co-condensed novolak resin, biphenyl-modified
phenol resin (polyvalent phenol compound in which a phenol nucleus
is connected through a bismethylene group), biphenyl-modified
naphthol resin (polyvalent naphthol compound in which a phenol
nucleus is connected through a bismethylene group),
aminotriazine-modified phenol resin (polyvalent phenol compound in
which phenol nucleus is connected through melamine or
benzoguanamine).
[0120] Among these compounds, those containing a lot of aromatic
skeletons in the molecular structure are preferable in view of the
flame retardant effect and, for example, a phenol novolak resin, a
cresol novolak resin, an aromatic hydrocarbon formaldehyde
resin-modified phenol resin, a phenol aralkyl resin, a naphthol
aralkyl resin, a naphthol novolak resin, a naphthol-phenol
co-condensed novolak resin, a naphthol-cresol co-condensed novolak
resin, a biphenyl-modified phenol resin, a biphenyl-modified
naphthol resin and an aminotriazine-modified phenol resin are
preferable because of excellent flame retardancy.
[0121] In the present invention, the above phenol resin used as an
essential component in epoxy resin composition (I) is preferable
and a novel phenol resin of the present invention is particularly
preferable because a remarkable effect of decreasing the dielectric
constant and dielectric dissipation factor is exerted. Furthermore,
the phenol resin composed of an alkoxy group-containing condensed
polycyclic aromatic hydrocarbon group (B) represented by the
structural formula (1'), a methylene group (X) represented by the
structural formula (2') and a phenolic hydroxyl group-containing
aromatic hydrocarbon group (P) represented by the formula (3) or
(4) is particularly preferable because a remarkable flame retardant
effect is exerted.
[0122] The contents of the epoxy resin and the curing agent in
epoxy resin composition of the present invention (II) are not
specifically limited. The content of an active group in the curing
agent is preferably within a range from 0.7 to 1.5 equivalents
based on 1 equivalent of the total of epoxy groups in the epoxy
resin containing the epoxy resin because the resulting cured
article is excellent in characteristics.
[0123] If necessary, curing accelerators can also be added to epoxy
resin composition of the present invention (II). Various curing
accelerators can be used and examples thereof include
phosphorous-based compound, tertiary amine, imidazole, organic acid
metal salt, Lewis acid and amine complex salt. When used as
semiconductor encapsulation materials, triphenylphosphine is
preferable in case of a phosphorous-based compound and
1,8-diazabicyclo-[5.4.0]-undecene (DBU) is preferable in case of a
tertiary amine because of excellent curability, heat resistance,
electrical characteristics and moisture resistant reliability.
[0124] In the above-described epoxy resin compositions (I) and (II)
of the present invention, since the resin itself has an excellent
effect of imparting flame retardancy according to selection of the
molecular structure of the epoxy resin or a curing agent thereof,
the cured article is excellent in flame retardancy even if a
conventionally use flame retardant is not mixed. However, in order
to exhibit more excellent flame retardancy, in the field of the
semiconductor encapsulation material, a non-halogen flame retardant
(C) containing substantially no halogen atom may be mixed as far as
moldability in the encapsulation step and reliability of the
semiconductor device are not deteriorated.
[0125] The epoxy resin composition containing such as non-halogen
flame retardant (C) substantially contains no halogen atom, but may
contain a trace amount (about 5000 ppm or less) of a halogen atom
due to impurities derived from epihalohydrin contained in the epoxy
resin.
[0126] Examples of the non-halogen flame retardant (C) include
phosphorous-based flame retardant, nitrogen-based flame retardant,
silicone-based flame retardant, inorganic-based flame retardant and
organic metal salt-based flame retardant and these flame retardant
are not specifically limited when used and may be used alone, or a
plurality of the same flame retardants may be used or different
flame retardants can be used in combination.
[0127] AS the phosphorous-based flame retardant, inorganic and
organic flame retardants can be used. Examples of the inorganic
compound include ammonium phosphates such as red phosphorus,
monoammonium phosphate, diammonium phosphate, triammonium phosphate
and ammonium polyphosphate; and inorganic nitrogen-containing
phosphorus compounds such as phosphoric acid amide.
[0128] For the purpose of preventing hydrolysis of red phosphorus,
it is preferably subjected to a surface treatment. Examples of the
method of a surface treatment include (i) a method of coating with
an inorganic compound such as magnesium hydroxide, aluminum
hydroxide, zinc hydroxide, titanium hydroxide, bismuth oxide,
bismuth hydroxide, bismuth nitrate or a mixture thereof, (ii) a
method of coating with an inorganic compound such as magnesium
hydroxide, aluminum hydroxide, zinc hydroxide or titanium
hydroxide, and a mixture of a thermosetting resin such as phenol
resin, (iii) and a method of double-coating a coating film made of
an inorganic compound such as magnesium hydroxide, aluminum
hydroxide, zinc hydroxide or titanium hydroxide with a
thermosetting resin such as phenol resin.
[0129] Examples of the organic phosphorous-based compound include
commodity organic phosphorous-based compounds such as phosphate
ester compound, phosphonic acid compound, phosphinic acid compound,
phosphine oxide compound, phospholan compound and organic
nitrogen-containing phosphorus compound; cyclic organic phosphorus
compounds such as
9,10-dihydro-9-oxa-10-phosphaphenanthrene=10-oxide,
10-(2,5-dihydrooxyphenyl)-10H-9-oxa-10-phsophaphenanthrene=10-oxide
and
10(2,7-dihydrooxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene=10-oxide;
and derivatives obtained by reacting the cyclic organic phosphorus
compound with a compound such as epoxy resin or phenol resin.
[0130] The amount is appropriately selected according to the kind
of the phosphorous-based flame retardant, other components of the
epoxy resin composition and the degree of desired flame retardancy.
When red phosphorus is used as the non-halogen flame retardant in
100 parts by mass of an epoxy resin composition containing an epoxy
resin, a curing agent, a non-halogen flame retardant and other
fillers and additives, the amount is preferably within a range from
0.1 to 2.0 parts by mass. When an organic phosphorous compound is
used, the amount is preferably within a range from 0.1 to 10.0
parts by mass, and particularly preferably from 0.5 to 6.0 parts by
mass.
[0131] When the phosphorous-based flame retardant is used, the
phosphorous-based flame retardant may be used in combination with
hydrotalcite, magnesium hydroxide, boron compound, zirconium oxide,
black dye, calcium carbonate, zeolite, zinc molybdate and activated
carbon.
[0132] Examples of the nitrogen-based flame retardant include
triazine compound, cyanuric acid compound, isocyanuric acid
compound and phenothiazine, and a triazine compound, a cyanuric
acid compound and an isocyanuric acid compound are preferable.
[0133] Examples of the triazine compound include, in addition to
melamine, acetoguanamine, benzoguanamine, melon, melam,
succinoguanamine, ethylenedimelamine, melamine polyphosphate and
triguanamine, (i) aminotriazine sulfate compound such as
guanylmelamine sulfate, melem sulfate or melam sulfate, (ii)
cocondensate of phenols such as phenol, cresol, xylenol,
butylphenol and nonylphenol, melamines such as melamine,
benzoguanamin, acetoguanamine and formguanamine, and formaldehyde,
(iii) mixture of the cocondensate (ii) and phenol resins such as
phenolformaldehyde condensate, and (iv) those obtained by modifying
the cocondensate (ii) and the mixture (iii) with tung oil or
isomerized linseed oil.
[0134] Specific examples of the cyanuric acid compound include
cyanuric acid and melamine cyanurate.
[0135] The amount of the nitrogen-based flame retardant is
appropriately selected according to the kind of the nitrogen-based
flame retardant, other components of the epoxy resin composition
and the degree of desired flame retardancy, and is preferably
within a range from 0.05 to 10 parts by mass, and particularly
preferably from 0.1 to 5 parts by mass, based on 100 parts by mass
of an epoxy resin composition containing an epoxy resin, a curing
agent, a non-halogen flame retardant and other fillers and
additives.
[0136] When the nitrogen-based flame retardant is used, a metal
hydroxide and a molybdenum compound may be used in combination.
[0137] The silicone-based flame retardant is not specifically
limited as far as it is an organic compound having a silicon atom,
and examples thereof include silicone oil, silicone rubber and
silicone resin.
[0138] The amount of the silicone-based flame retardant is
appropriately selected according to the kind of the silicone-based
flame retardant, other components of the epoxy resin composition
and the degree of desired flame retardancy, and is preferably
within a range from 0.05 to 20 parts by mass based on 100 parts by
mass of an epoxy resin composition containing an epoxy resin, a
curing agent, a non-halogen flame retardant and other fillers and
additives. When the silicone-based flame retardant is used, a
molybdenum compound and alumina may be used in combination.
[0139] Examples of the inorganic-based flame retardant include
metal hydroxide, metal oxide, metal carbonate compound, metal
powder, boron compound and low melting point glass.
[0140] Specific examples of the metal hydroxide include aluminum
hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium
hydroxide, barium hydroxide and zirconium hydroxide.
[0141] Specific examples of the metal oxide include zinc molybdate,
molybdenum trioxide, zinc stannate, tin oxide, aluminum oxide, iron
oxide, titanium oxide, manganese oxide, zirconium oxide, zinc
oxide, molybdenum oxide, cobalt oxide, bismuth oxide, chromium
oxide, nickel oxide, copper oxide and tungsten oxide.
[0142] Specific examples of the metal carbonate compound include
zinc carbonate, magnesium carbonate, calcium carbonate, barium
carbonate, basic magnesium carbonate, aluminum carbonate, iron
carbonate, cobalt carbonate and titanium carbonate.
[0143] Specific examples of the metal powder include aluminum,
iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth,
chromium, nickel, copper, tungsten and tin powders.
[0144] Specific examples of the boron compound include zinc borate,
zinc metaborate, barium metaborate, boric acid and borax.
[0145] Specific examples of the low melting point glass include
Seaplea (Bokusui Brown Co Ltd.), hydrated glass
SiO.sub.2--MgO-H.sub.2O, PbO-B.sub.2O.sub.3-based,
ZnO-P.sub.2O.sub.5--MgO-based,
P.sub.2O.sub.5-B.sub.2O.sub.3--PbO--MgO-based, P--Sn--O--F-based,
PbO-V.sub.2O.sub.5--TeO.sub.2-based,
Al.sub.2O.sub.3--H.sub.2O-based and lead borosilicate-based glassy
compounds.
[0146] The amount of the inorganic-based flame retardant is
appropriately selected according to the kind of the inorganic-based
flame retardant, other components of the epoxy resin composition
and the degree of desired flame retardancy, and is preferably
within a range from 0.05 to 20 parts by mass, and particularly
preferably from 0.5 to 15 parts by mass, based on 100 parts by mass
of an epoxy resin composition containing an epoxy resin, a curing
agent, a non-halogen flame retardant and other fillers and
additives.
[0147] Examples of the organic metal salt-based flame retardant
include ferrocene, acetylacetonate metal complex, organic metal
carbonyl compound, organic cobalt salt compound, organic sulfonic
acid metal salt, and compound obtained by ionic bonding or
coordinate bonding of a metal atom and an aromatic compound or a
heterocyclic compound.
[0148] The amount of the organic metal salt-based flame retardant
is appropriately selected according to the kind of the organic
metal salt-based flame retardant, other components of the epoxy
resin composition and the degree of desired flame retardancy, and
is preferably within a range from 0.005 to 10 parts by mass based
on 100 parts by mass of an epoxy resin composition containing an
epoxy resin, a curing agent, a non-halogen flame retardant and
other fillers and additives.
[0149] If necessary, the epoxy resin composition of the present
invention can contain inorganic fillers. Examples of the inorganic
filler include fused silica, crystalline silica, alumina, silicon
nitride and aluminum hydroxide. When the amount of the inorganic
filler is particularly large, fused silica is preferably used. The
fused silica can be used in a crushed or spherical form, and the
spherical form is preferably used so as to increase the amount of
the fused silica and to suppress an increase in melt viscosity of a
molding material. To further increase the amount of the spherical
silica, it is preferred to appropriately adjust particle size
distribution of the spherical silica. Taking account of flame
retardancy, the content of the filler is preferably high and is
particularly preferably 65% by mass or more based on the total
amount of the epoxy resin composition. When used in the conductive
paste, a conductive filler such as silver powder or copper powder
can be used.
[0150] To epoxy resin composition (I) or (II) of the present
invention, various additives such as silane coupling agent,
releasant, pigment and emulsifier can be added, if necessary.
[0151] Epoxy resin composition (I) or (II) of the present invention
can be obtained by uniformly mixing the above-described components.
The epoxy resin composition of the present invention, which
contains an epoxy resin of the present invention, a curing agent
and, if necessary, a curing accelerator, can be easily formed into
a cured article by way of the common methods. Examples of the cured
article include molded cured articles such as laminate, cast
article, adhesive layer, coating film and film.
[0152] Examples of uses of the epoxy resin composition of the
present invention include semiconductor encapsulation materials,
resin compositions used for laminates and electronic circuit
boards, resin casting materials, adhesives, interlayer insulation
materials for buildup substrates, and coating materials such as
insulating paint. The epoxy resin composition of the present
invention can be preferably used as semiconductor encapsulation
materials.
[0153] The epoxy resin composition for semiconductor encapsulation
material is obtained by the following procedure. That is, an epoxy
resin and compounding agents such as curing agent and filler are
sufficiently mixed using an extruder, a kneader or a roll to obtain
a uniform melt-mixing type epoxy resin composition. In that case,
silica is usually used as the filler and the amount of the filler
is preferably within a range from 30 to 95 parts by mass based on
100 parts by mass of the epoxy resin composition. To improve flame
retardancy, moisture resistance and solder cracking resistance and
to decrease the linear expansion coefficient, the amount of the
filler is particularly preferably 70 parts by mass or more. To
noticeably enhance the effect, the amount of the filler is adjusted
to 80 parts by mass or more. In case of semiconductor package
molding, the composition is molded by casting or using a transfer
molding machine or an injection molding machine and then heated at
50 to 200.degree. C. for 2 to 10 hours to obtain a semiconductor
device as a molded article.
[0154] The epoxy resin composition of the present invention can be
formed into a composition for printed circuit board, for example, a
resin composition for prepreg. According to the viscosity, the
epoxy resin composition can be used without using a solvent, and
the resin composition for prepreg is preferably prepared by forming
into a varnish using an organic solvent. As the organic solvent, a
polar solvent having a boiling point of 160.degree. C. or lower
such as methyl ethyl ketone, acetone or dimethyl formamide is
preferably used, and these organic solvents can be used alone or in
combination. A prepreg as a cured article can be obtained by
impregnating various reinforcing base materials such as paper,
glass cloth, glass nonwoven fabric, aramid paper, aramid cloth,
glass mat and glass roving cloth with the resulting varnish and by
heating at a temperature corresponding to the kind of the solvent,
preferably 50 to 170.degree. C. The contents of the resin
composition and the reinforcing base material are not specifically
limited, and the content of the resin in the prepreg is preferably
adjusted within a range from 20 to 60% by mass. When a
copper-cladded laminate is produced using the epoxy resin
composition, the copper-cladded laminate can be obtained by laying
the resulting prepregs one upon another using a conventional method
and appropriately laying a copper foil thereon, followed by
press-contacting with heating at 170 to 250.degree. C. under
pressure of 1 to 10 MPa for 10 minutes to 3 hours.
[0155] When the epoxy resin composition of the present invention is
used as a resist ink, for example, a cationic polymerization
catalyst is used as a curing agent of epoxy resin composition (II)
and a pigment, talc and a filler are added to give a composition
for resist ink, and then the composition is coated onto a printed
board using a screen printing method to give a resist ink cured
article.
[0156] When the epoxy resin composition of the present invention is
used as a conductive paste, for example, a method wherein
conductive fine particles are dispersed in the epoxy resin
composition to give a composition for anisotropic conductive layer;
or a method wherein the composition is parepared into a paste resin
composition for connection of circuits, which is liquid at room
temperature, or an anisotropic conductive adhesive can be
adopted.
[0157] An interlayer insulation material for buildup substrate can
be obtained from the epoxy resin composition of the present
invention in the following manner. That is, the curable resin
composition obtained by appropriately mixing a rubber, a filler or
the like is coated onto a wiring board having an inner layer
circuit formed thereon using a spray coating method or a curtain
coating method, and then cured. If necessary, predetermined holes
such as throughholes are formed and the wiring board is treated
with a roughening agent. The surface is washed with hot water to
form irregularity and the wiring board is plated with metal such as
copper. The plating method is preferably electroless plating or
electroplating treatment, and examples of the roughening agent
include oxidizing agent, alkali and organic solvent. Such an
operation is optionally repeated successively, and a buldup
substrate can be formed by way of alternating layers of a resin
insulating layer and a conductive layer having a predetermined
circuit pattern. Throughholes are formed after forming the
outermost resin insulating layer. It is also possible to produce a
buildup substrate without conducting the step of forming a
roughened surface and a plating step by contact-bonding a copper
foil coated with a semicured resin composition on a wiring board
having an inner layer circuit formed thereon with heating at 170 to
250.degree. C.
[0158] The cured article of the present invention may be obtained
by a conventional method of curing an epoxy resin composition. For
example, heating temperature conditions may be appropriately
selected by the kind of curing agents to be used in combination and
purposes, and the composition obtained by the above method may be
heated at a temperature within a range from room temperature to
about 250.degree. C. The epoxy resin composition may be molded by a
conventional method and the conditions peculiar to the epoxy resin
composition of the present invention are not required.
[0159] Therefore, an environmentally friendly epoxy resin material
capable of exhibiting excellent flame retardancy can be obtained by
using the phenol resin even if a halogen-based flame retardant is
not used. Excellent dielectric characteristics can realize an
increase in operation speed of a high-frequency device and enable
molecular design corresponding to the level of the above-described
objective performances. The phenol resin can be produced by the
method for producing of the present invention easily and
effectively.
EXAMPLES
[0160] The present invention will now be described in detail by way
of examples and comparative examples. In the following examples and
comparative examples, parts and percentages are by mass unless
otherwise specified. Melt viscosity at 150.degree. C., GPC, NMR and
MS spectrum were measured under the following conditions.
1) Melt viscosity at 150.degree. C.: in accordance with ASTM D4287
2) Method for measurement of softening point: JIS K7234
3) GPC:
[0161] Apparatus: HLC-8220 GPC manufactured by Tosoh
Corporation
[0162] Column: TSK-GEL G2000HXL+G2000HXL+G3000HXL+G4000HXL
manufactured by Tosoh Corporation
[0163] Solvent: tetrahydrofuran
[0164] Flow rate: 1 ml/min
[0165] Detector: RI
4) NMR: NMR GSX270 manufactured by JEOL Ltd. 5) MS: Double-focusing
mass spectrometer AX505H (FD505H) manufactured by JEOL Ltd.
[0166] In the examples and comparative examples, "P-X-B", "E-X-B"
and "B-X-B" mean a structure of a compound including the following
structural units wherein P is a structural unit of a phenolic
hydroxyl group-containing aromatic hydrocarbon group (P), E is a
structural unit of a glycidyloxy group-containing aromatic
hydrocarbon group (E), B is an alkoxy group-containing condensed
polycyclic aromatic hydrocarbon group (B), and X is a structural
unit of a divalent hydrocarbon group (X) selected from methylene,
an alkylidene group and an aromatic hydrocarbon
structure-containing methylene group.
Example 1
Synthesis of Phenol Resin (A-1)
[0167] In a flask equipped with a thermometer, a condenser tube, a
distilling tube, a nitrogen introducing tube and a stirrer, 432.4 g
(4.00 mols) of o-cresol, 158.2 g (1.00 mols) of
2-methoxynaphthalene and 179.3 g (2.45 mols) of 41%
paraformaldehyde were charged, mixed with 9.0 g of oxalic acid and
then reacted at 100.degree. C. for 3 hours by heating to
100.degree. C. While collecting water using a distilling tube, 73.2
g (1.00 mols) of 41% paraform was added dropwise over one hour.
After the completion of dropwise addition, the reaction was
conducted at 150.degree. C. for 2 hours by heating to 150.degree.
C. over one hour. After the completion of the reaction, 1500 g of
methyl isobutyl ketone was further added and the reaction solution
was transferred to a separatory funnel, followed by washing with
water. After washing with water until rinse water shows neutrality,
unreacted o-cresol, 2-methoxynaphthalene and methyl isobutyl ketone
were removed from the organic layer with heating under reduced
pressure to obtain 531 g of a phenol resin (A-1) having a
structural unit represented by the following structural
formula:
##STR00015##
The resulting phenol resin had a softening point of 76.degree. C.
(B&R method), a melt viscosity (measuring method: ICI
viscometer method, measured temperature: 150.degree. C.) of 1.0
dPas and a hydroxyl group equivalent of 164 g/eq.
[0168] A GPC chart of the resulting phenol resin is shown in FIG.
1, a C.sup.13 NMR chart is shown in FIG. 2 and an MS spectrum is
shown in FIG. 3. GPC analysis revealed that the content of a
compound having a structure represented by "P-X-B" was 11% by mass
and the content of a compound having a structure represented by
"B-X-B" was 1% by mass. As a result of the measurement of the mass
of the recovered unreacted o-cresol and 2-methoxynaphthalene and
the measurement of a hydroxyl group of the resulting phenol resin,
it was confirmed that a molar ratio of a structural unit of a
phenolic hydroxyl group-containing aromatic hydrocarbon group to a
structural unit of an alkoxy group-containing condensed polycyclic
aromatic hydrocarbon group in the phenol resin, the former/the
latter, was 79/21. The remaining of methoxy group was confirmed
from a signal of a methoxy group observed at 55 ppm in NMR and it
is confirmed from a hydroxyl group equivalent that the methoxy
group in the compound is not decomposed. Also it could be confirmed
that the resulting resin has a structure represented by "B-X-" at
the molecular end.
Example 2
Synthesis of Phenol Resin (A-2)
[0169] In a flask equipped with a thermometer, a condenser tube, a
distilling tube, and a stirrer, 169.4 g (1.80 mols) of phenol, 31.6
g (0.20 mols) of 2-methoxynaphthalene and 32.6 g (1.00 mols) of 92%
paraformaldehyde were charged, mixed with 5.0 g of oxalic acid,
reacted at 100.degree. C. for one hour by heating to 100.degree. C.
over one hour, and then reacted at 140.degree. C. for one hour.
After the completion of the reaction, 700 g of methyl isobutyl
ketone was further added and the reaction solution was transferred
to a separatory funnel, followed by washing with water. After
washing with water until rinse water shows neutrality, unreacted
phenol, 2-methoxynaphthalene and methyl isobutyl ketone were
removed from the organic layer with heating under reduced pressure
to obtain 149 g of a phenol resin (A-2) having a structural unit
represented by the following structural formula:
##STR00016##
The resulting phenol resin had a softening point of 78.degree. C.
(B&R method), a melt viscosity (measuring method: ICI
viscometer method, measured temperature: 150.degree. C.) of 1.2
dPas and a hydroxyl group equivalent of 122 g/eq.
[0170] A GPC chart of the resulting phenol resin is shown in FIG.
4, a C.sup.13 NMR chart is shown in FIG. 5 and an MS spectrum is
shown in FIG. 6. GPC analysis revealed that the content of a
compound having a structure represented by "P-X-B" was 7% by mass
and the content of a compound having a structure represented by
"B-X-B" was trace. As a result of the measurement of the mass of
the recovered unreacted phenol and 2-methoxynaphthalene and the
measurement of a hydroxyl group of the resulting phenol resin, it
was confirmed that a molar ratio of a structural unit of a phenolic
hydroxyl group-containing aromatic hydrocarbon group to a
structural unit of an alkoxy group-containing condensed polycyclic
aromatic hydrocarbon group in the phenol resin, the former/the
latter, was 85/15. It was confirmed from a signal of a methoxy
group observed at 55 ppm in NMR and a hydroxyl group equivalent
that the methoxy group in the compound is not decomposed. Also it
could be confirmed that the resulting resin has a structure
represented by "B-X-" at the molecular end.
Example 3
Synthesis of Phenol Resin (A-3)
[0171] In a flask equipped with a thermometer, a condenser tube, a
distilling tube, and a stirrer, 141.2 g (1.50 mols) of phenol, 79.1
g (0.50 mols) of 2-methoxynaphthalene and 32.6 g (1.00 mols) of 92%
paraformaldehyde were charged, mixed with 5.0 g of oxalic acid,
reacted at 100.degree. C. for 2 hours by heating to 100.degree. C.
over one hour. After the completion of the reaction, 700 g of
methyl isobutyl ketone was further added and the reaction solution
was transferred to a separatory funnel, followed by washing with
water. After washing with water until rinse water shows neutrality,
unreacted phenol, 2-methoxynaphthalene and methyl isobutyl ketone
were removed from the organic layer with heating under reduced
pressure to obtain 174 g of a phenol resin (A-3) having a
structural unit represented by the following structural
formula:
##STR00017##
The resulting phenol resin had a softening point of 74.degree. C.
(B&R method), a melt viscosity (measuring method: ICI
viscometer method, measured temperature: 150.degree. C.) of 1.0
dPas and a hydroxyl group equivalent of 200 g/eq.
[0172] A GPC chart of the resulting phenol resin is shown in FIG.
7. GPC analysis revealed that the content of a compound having a
structure represented by "P-X-B" was 22% by mass and the content of
a compound having a structure represented by "B-X-B" was 4% by
mass. As a result of the measurement of the mass of the recovered
unreacted phenol and 2-methoxynaphthalene and the measurement of a
hydroxyl group of the resulting phenol resin, it was confirmed that
a molar ratio of a structural unit of a phenolic hydroxyl
group-containing aromatic hydrocarbon group to a structural unit of
an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group in the phenol resin, the former/the latter, was
65/35. Also it could be confirmed that the resulting resin has a
structure represented by "B-X-" at the molecular end.
Example 4
Synthesis of Phenol Resin (A-4)
[0173] In a flask equipped with a thermometer, a condenser tube, a
distilling tube, a nitrogen introducing tube and a stirrer, 432.4 g
(4.00 mols) of o-cresol, 158.2 g (1.00 mols) of
2-methoxynaphthalene and 212.2 g (2.00 mols) of benzaldehyde were
charged, mixed with 9.0 g of paratoluenesulfonic acid, reacted at
145.degree. C. for 5 hours by heating to 145.degree. C. over one
hour. While collecting water using a distilling tube, the reaction
was conducted at 170.degree. C. for 2 hours by heating to
170.degree. C. over one hour. After the completion of the reaction,
1500 g of methyl isobutyl ketone was further added and the reaction
solution was transferred to a separatory funnel, followed by
washing with water. After washing with water until rinse water
shows neutrality, unreacted o-cresol, 2-methoxynaphthalene and
methyl isobutyl ketone were removed from the organic layer with
heating under reduced pressure to obtain 545 g of a phenol resin
(A-4) having a structural unit represented by the following
structural formula:
##STR00018##
[0174] The resulting phenol resin had a softening point of
99.degree. C. (B&R method), a melt viscosity (measuring method:
ICI viscometer method, measured temperature: 150.degree. C.) of 5.0
dPas and a hydroxyl group equivalent of 219 g/eq.
[0175] A GPC chart of the resulting phenol resin is shown in FIG.
8. GPC analysis revealed that the content of a compound having a
structure represented by "P-X-B" was 12% by mass and the content of
a compound having a structure represented by "B-X-B" was 1% by
mass. As a result of the measurement of the mass of the recovered
unreacted o-cresol and 2-methoxynaphthalene and the measurement of
a hydroxyl group of the resulting phenol resin, it was confirmed
that a molar ratio of a structural unit of a phenolic hydroxyl
group-containing aromatic hydrocarbon group to a structural unit of
an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group in the phenol resin, the former/the latter, was
80/20. Also it could be confirmed that the resulting resin has a
structure represented by "B-X-" at the molecular end.
Example 5
Synthesis of Phenol Resin (A-5)
[0176] In the same manner as in Example 3, except that 173.0 g
(1.60 mols) of phenol and 63.3 g (0.40 mols) of
2-methoxynaphthalene were used, 177 g of a phenol resin (A-5)
having a structural unit represented by the following structural
formula:
##STR00019##
was obtained. The resulting phenol resin had a softening point of
67.degree. C. (B&R method), a melt viscosity (measuring method:
ICI viscometer method, measured temperature: 150.degree. C.) of 0.4
dPas and a hydroxyl group equivalent of 170 g/eq. A GPC chart of
the resulting phenol resin is shown in FIG. 9. GPC analysis
revealed that the content of a compound having a structure
represented by "P-X-B" was 24% by mass and the content of a
compound having a structure represented by "B-X-B" was 3% by mass.
As a result of the measurement of the mass of the recovered
unreacted phenol and 2-methoxynaphthalene and the measurement of a
hydroxyl group of the resulting phenol resin, it was confirmed that
a molar ratio of a structural unit of a phenolic hydroxyl
group-containing aromatic hydrocarbon group to a structural unit of
an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group in the phenol resin, the former/the latter, was
74/26. Also it could be confirmed that the resulting resin has a
structure represented by "B-X-" at the molecular end.
Example 6
Synthesis of Phenol Resin (A-6)
[0177] In the same manner as in Example 3, except that 334.0 g
(1.67 mols) of bisphenol F in place of the phenol in Example 3 and
131.3 g (0.83 mols) of 2-methoxynaphthalene were used, 350 g of a
phenol resin (A-6) having a structural unit represented by the
following structural formula:
##STR00020##
was obtained. The resulting phenol resin had a softening point of
64.degree. C. (B&R method), a melt viscosity (measuring method:
ICI viscometer method, measured temperature: 150.degree. C.) of 0.5
dPas and a hydroxyl group equivalent of 139 g/eq. A GPC chart of
the resulting phenol resin is shown in FIG. 10. GPC analysis
revealed that the content of a compound having a structure
represented by "P-X-B" was 0% by mass and the content of a compound
having a structure represented by "B-X-B" was 4% by mass. As a
result of the measurement of the mass of the recovered unreacted
2-methoxynaphthalene and the measurement of a hydroxyl group of the
resulting phenol resin, it was confirmed that a molar ratio of a
structural unit of a phenolic hydroxyl group-containing aromatic
hydrocarbon group to a structural unit of an alkoxy
group-containing condensed polycyclic aromatic hydrocarbon group in
the phenol resin, the former/the latter, was 85/15. Also it could
be confirmed that the resulting resin has a structure represented
by "B-X-" at the molecular end.
Example 7
Synthesis of Phenol Resin (A-7)
[0178] In a flask equipped with a thermometer, a condenser tube, a
distilling tube, a nitrogen introducing tube and a stirrer, 376.4 g
(4.00 mols) of phenol, 158.2 g (1.00 mols) of 2-methoxynaphthalene
and 159.2 g (1.50 mols) of benzaldehyde were charged, mixed with
9.0 g of paratoluenesulfonic acid, reacted at 145.degree. C. for 5
hours by heating to 145.degree. C. over one hour. While collecting
water using a distilling tube, the reaction was conducted at
170.degree. C. for 2 hours by heating to 170.degree. C. over one
hour. After the completion of the reaction, 1500 g of methyl
isobutyl ketone was further added and the reaction solution was
transferred to a separatory funnel, followed by washing with water.
After washing with water until rinse water shows neutrality,
unreacted phenol, 2-methoxynaphthalene and methyl isobutyl ketone
were removed from the organic layer with heating under reduced
pressure to obtain a phenol resin (A-7) having a structural unit
represented by the following structural formula:
##STR00021##
[0179] The resulting phenol resin had a softening point of
63.degree. C. (B&R method), a melt viscosity (measuring method:
ICI viscometer method, measured temperature: 150.degree. C.) of 1.2
dPas and a hydroxyl group equivalent of 288 g/eq.
[0180] A GPC chart of the resulting phenol resin is shown in FIG.
11. As a result of the measurement of the mass of the recovered
unreacted phenol and 2-methoxynaphthalene and the measurement of a
hydroxyl group of the resulting phenol resin, it was confirmed that
a molar ratio of a structural unit of a phenolic hydroxyl
group-containing aromatic hydrocarbon group to a structural unit of
an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group in the phenol resin, the former/the latter, was
80/20.
Example 8
Synthesis of Phenol Resin (A-8)
[0181] In the same manner as in Example 7, except that 182.2 g
(1.00 mols) of 4-biphenylaldehyde was used in place of benzaldehyde
in Example 7, a phenol resin (A-8) having a structural unit
represented by the following structural formula:
##STR00022##
was obtained. The resulting phenol resin had a softening point of
61.degree. C. (B&R method), a melt viscosity (measuring method:
ICI viscometer method, measured temperature: 150.degree. C.) of 1.1
dPas and a hydroxyl group equivalent of 323 g/eq.
[0182] A GPC chart of the resulting phenol resin is shown in FIG.
12. As a result of the measurement of the mass of the recovered
unreacted phenol and 2-methoxynaphthalene and the measurement of a
hydroxyl group of the resulting phenol resin, it was confirmed that
a molar ratio of a structural unit of a phenolic hydroxyl
group-containing aromatic hydrocarbon group to a structural unit of
an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group in the phenol resin, the former/the latter, was
80/20.
Synthesis Example 1
Synthesis of compound of Japanese Unexamined Patent Application,
First Publication No. 2004-010700
[0183] 108.0 g (1.0 mols) of orthocresol and 132.0 g (2.2 mols) of
an aqueous 50% formalin solution were charged in a reaction vessel
and 133.3 g (1.0 mols) of an aqueous 30% sodium hydroxide solution
was added dropwise over one hour while maintaining at 30.degree. C.
or lower. After the completion of the dropwise addition, the
reaction was conducted for 2 hours by heating to 40.degree. C.
Then, 126.0 g (1.0 mols) of dimethyl sulfate was added dropwise at
40.degree. C. over one hour and the reaction was conducted for 2
hours by heating to 60.degree. C., thereby to synthesize a resol
resin wherein a phenolic hydroxyl group is methoxylated. After the
completion of the reaction, the aqueous layer was separated and
282.0 g (3.0 mols) of phenol and 9.1 g of 35% hydrochloric acid
were added, followed by the reaction at 90.degree. C. for 4 hours.
After the completion of the reaction, the reaction solution was
neutralized with 6.0 g of an aqueous 25% ammonia solution and a
neutralized salt was removed by washing with water. The unreacted
phenol was removed by heating to 200.degree. C. under 60 mmHg to
obtain a phenol resin (A-9). The resulting phenol resin had a
softening point of 77.degree. C. (B&R method), a melt viscosity
(measuring method: ICI viscometer method, measured temperature:
150.degree. C.) of 0.8 dPas and a hydroxyl group equivalent of 160
g/eq.
Synthesis Example 2
[0184] In a 500 ml four-necked flask, 144 g (1.0 mols) of
2-naphthol, 200 g of isopropyl alcohol and 8.2 g of 49% sodium
hydroxide were charged and then heated to 40.degree. C. in a
nitrogen gas flow while stirring. After heating, the temperature
was raised to 60.degree. C. while adding dropwise 37 g (0.5 mols)
of 41% formalin over 2 hours and then the reaction was conducted at
60.degree. C. for 2 hours. As a result, a compound represented by
the following structural formula:
##STR00023##
was obtained and a methylol compound was not obtained.
Example 9
Synthesis of Epoxy Resin (E-1)
[0185] In a flask equipped with a thermometer, a dropping funnel, a
condenser tube and a stirrer, 164 g (hydroxyl group: 1 equivalent)
of the phenol resin (A-1) obtained in Example 1, 463 g (5.0 mols)
of epichlorohydrin, 139 g of n-butanol and 2 g of
tetraethylbenzylammonium chloride were charged and dissolved while
purging with a nitrogen gas. After heating to 65.degree. C., the
pressure was reduced to the pressure at which an azeotrope is
produced, and then 90 g (1.1 mols) of an aqueous 49% sodium
hydroxide solution was added dropwise over 5 hours. Under the same
conditions, stirring was continued for 0.5 hours. The distillate
produced by azeotropy during stirring was separated by a Dean-Stark
trap and the aqueous layer was removed, and then the reaction was
conducted while returning the oil layer into the reaction system.
Then, the unreacted epichlorohydrin was distilled off by
distillation under reduced pressure. The resulting crude epoxy
resin was dissolved in 590 g of methyl isobutyl ketone and 177 g of
n-butanol. To the solution, 10 g of an aqueous 10% sodium hydroxide
solution was added. After reacting at 80.degree. C. for 2 hours,
the solution was repeatedly washed with 150 g of water three times
until the pH of the wash becomes neutral. The system was dehydrated
by azeotropy and, after precise filtration, the solvent was
distilled off under reduced pressure to obtain 198 g of an epoxy
resin (E-1) having a structural unit represented by the following
structural formula.
##STR00024##
The resulting epoxy resin had a softening point of 58.degree. C.
(B&R method), a melt viscosity (measuring method: ICI
viscometer method, measured temperature: 150.degree. C.) of 1.0
dPas and an epoxy equivalent of 252 g/eq.
[0186] A GPC chart of the resulting epoxy resin is shown in FIG.
13, a .sup.13C NMR chart is shown in FIG. 14 and an MS spectrum is
shown in FIG. 15. GPC analysis revealed that the content of a
compound having a structure represented by "E-X-B" was 10% by mass
and the content of a compound having a structure represented by
"B-X-B" was 1% by mass. It was confirmed the remaining of methoxy
group from a signal of a methoxy group observed at 55 ppm in NMR
and an epoxy equivalent that the methoxy group in the compound is
not decomposed. A molar ratio of a structural unit of a glycidyloxy
group-containing aromatic hydrocarbon group to a structural unit of
an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group in the epoxy resin was determined from the
results of the measurement of the mass of the recovered unreacted
o-cresol and 2-methoxynaphthalene in case of producing the phenol
resin (A-1) and the measurement of a hydroxyl group of the
resulting phenol resin. As a result, a ratio of the former/the
latter was 79/21. Also it could be confirmed that the resulting
resin has a structure represented by "B-X-" at the molecular
end.
Example 10
Synthesis of Epoxy Resin (E-2)
[0187] In the same manner as in Example 9, except that the phenol
resin (A-1) was replaced by 122 g (hydroxyl group: 1 equivalent) of
the phenol resin (A-2) obtained in Example 2, 160 g of an epoxy
resin (E-2) having a structural unit represented by the following
structural formula:
##STR00025##
was obtained by epoxidation reaction.
[0188] The resulting epoxy resin had a softening point of
60.degree. C. (B&R method), a melt viscosity (measuring method:
ICI viscometer method, measured temperature: 150.degree. C.) of 1.0
dPas and an epoxy equivalent of 200 g/eq.
[0189] A GPC chart of the resulting epoxy resin is shown in FIG.
16, a .sup.13C NMR chart is shown in FIG. 17 and an MS spectrum is
shown in FIG. 18. GPC analysis revealed that the content of a
compound having a structure represented by "E-X-B" was 6% by mass
and the content of a compound having a structure represented by
"B-X-B" was trace. It was confirmed the remaining of methoxy group
from a signal of a methoxy group observed at 55 ppm in NMR and an
epoxy equivalent that the methoxy group in the compound is not
decomposed. A molar ratio of a structural unit of a glycidyloxy
group-containing aromatic hydrocarbon group to a structural unit of
an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group in the epoxy resin was determined from the
results of the measurement of the mass of the recovered unreacted
phenol and 2-methoxynaphthalene in case of producing the phenol
resin (A-2) and the measurement of a hydroxyl group of the
resulting phenol resin. As a result, a ratio of the former/the
latter was 92/8. Also it could be confirmed that the resulting
resin has a structure represented by "B-X-" at the molecular
end.
Example 11
Synthesis of Epoxy Resin (E-3)
[0190] In the same manner as in Example 9, except that the phenol
resin (A-1) was replaced by 200 g (hydroxyl group: 1 equivalent) of
the phenol resin (A-3) obtained in Example 3, 230 g of an epoxy
resin (E-3) having a structural unit represented by the following
structural formula:
##STR00026##
was obtained by epoxidation reaction. The resulting epoxy resin had
a softening point of 55.degree. C. (B&R method), a melt
viscosity (measuring method: ICI viscometer method, measured
temperature: 150.degree. C.) of 0.8 dPas and an epoxy equivalent of
290 g/eq. A molar ratio of a structural unit of a glycidyloxy
group-containing aromatic hydrocarbon group to a structural unit of
an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group in the epoxy resin was determined from the
results of the measurement of the mass of the recovered unreacted
phenol and 2-methoxynaphthalene in case of producing the phenol
resin (A-3) and the measurement of a hydroxyl group of the
resulting phenol resin. As a result, a ratio of the former/the
latter was 65/35.
Example 1
Synthesis of Epoxy Resin (E-4)
[0191] In the same manner as in Example 9, except that the phenol
resin (A-1) was replaced by 219 g (hydroxyl group: 1 equivalent) of
the phenol resin (A-4) obtained in Example 4, 247 g of an epoxy
resin (E-4) having a structural unit represented by the following
structural formula:
##STR00027##
was obtained by epoxidation reaction. The resulting epoxy resin had
a softening point of 78.degree. C. (B&R method), a melt
viscosity (measuring method: ICI viscometer method, measured
temperature: 150.degree. C.) of 2.0 dPas and an epoxy equivalent of
298 g/eq.
[0192] A GPC chart of the resulting epoxy resin is shown in FIG.
19. GPC analysis revealed that the content of a compound having a
structure represented by "E-X-B" was 11% by mass and the content of
a compound having a structure represented by "B-X-B" was 1% by
mass. A molar ratio of a structural unit of a glycidyloxy
group-containing aromatic hydrocarbon group to a structural unit of
an alkoxy group-containing condensed polycyclic aromatic
hydrocarbon group in the epoxy resin was determined from the
results of the measurement of the mass of the recovered unreacted
o-cresol and 2-methoxynaphthalene in case of producing the phenol
resin (A-4) and the measurement of a hydroxyl group of the
resulting phenol resin. As a result, a ratio of the former/the
latter was 80/20. Also it could be confirmed that the resulting
resin has a structure represented by "B-X-" at the molecular
end.
Synthesis Example 3
[0193] In a flask equipped with a thermometer, a dropping funnel, a
condenser tube and a stirrer, 168 parts of Milex XLC-4L
manufactured by Mitsui Chemicals Co., Ltd., 463 g (5.0 mols) of
epichlorohydrin, 139 g of n-butanol and 2 g of
tetraethylbenzylammonium chloride were charged and dissolved while
purging with a nitrogen gas. After heating to 65.degree. C., the
pressure was reduced to the pressure at which an azeotrope is
produced, and then 90 g (1.1 mols) of an aqueous 49% sodium
hydroxide solution was added dropwise over 5 hours. Under the same
conditions, stirring was continued for 0.5 hours. The distillate
produced by azeotropy during stirring was separated by a Dean-Stark
trap and the aqueous layer was removed, and then the reaction was
conducted while returning the oil layer into the reaction system.
Then, the unreacted epichlorohydrin was distilled off by
distillation under reduced pressure. The resulting crude epoxy
resin was dissolved in 590 g of methyl isobutyl ketone and 177 g of
n-butanol. To the solution, 10 g of an aqueous 10% sodium hydroxide
solution was added. After reacting at 80.degree. C. for 2 hours,
the solution was repeatedly washed with 150 g of water three times
until the pH of the wash becomes neutral. The system was dehydrated
by azeotropy and, after precise filtration, the solvent was
distilled off under reduced pressure to obtain an epoxy resin (E-5)
having a structural unit represented by the following structural
formula.
##STR00028##
The resulting epoxy resin had an epoxy equivalent of 241 g/eq.
Synthesis Example 4 (Synthesis of epoxy resin described in Japanese
Unexamined Patent Application, First Publication No.
2003-201333)
[0194] In a 1 liter four-necked flask equipped with a stirrer and a
heater, 152 g (1.0 mols) of trimethylhydroquinone was dissolved in
a solvent mixture of 500 g of toluene and 200 g of ethylene glycol
monoethyl ether. To the solution, 4.6 g of paratoluenesulfonic acid
was added and 64 g (0.6 mols) of 41% benzaldehyde was added
dropwise while paying attention to heat generation. While distilled
off moisture, the solution was stirred at 100 to 120.degree. C. for
15 hours. After cooling, the precipitated crystal was collected by
filtration, repeatedly washed with water until the filtrate becomes
neutral, and then dried to obtain 175 g of a phenol resin (GPC
purity: 99%).
[0195] In a flask equipped with a thermometer, a dropping funnel, a
condenser tube and a stirrer, 175 g of a phenol resin, 463 g (5.0
mols) of epichlorohydrin, 53 g of n-butanol and 2.3 g of
tetraethylbenzylammonium chloride were charged and dissolved while
purging with a nitrogen gas. After heating to 65.degree. C., the
pressure was reduced to the pressure at which an azeotrope is
produced, and then 82 g (1.0 mols) of an aqueous 49% sodium
hydroxide solution was added dropwise over 5 hours. Under the same
conditions, stirring was continued for 0.5 hours.
[0196] The distillate produced by azeotropy during stirring was
separated by a Dean-Stark trap and the aqueous layer was removed,
and then the reaction was conducted while returning the oil layer
into the reaction system. Then, the unreacted epichlorohydrin was
distilled off by distillation under reduced pressure. The resulting
crude epoxy resin was dissolved in 550 g of methyl isobutyl ketone
and 55 g of n-butanol. To the solution, 15 g of an aqueous 10%
sodium hydroxide solution was added. After reacting at 80.degree.
C. for 2 hours, the solution was repeatedly washed with 100 g of
water three times until the pH of the wash becomes neutral. The
system was dehydrated by azeotropy and, after precise filtration,
the solvent was distilled off under reduced pressure to obtain an
epoxy resin (E-6) represented by the following structural
formula.
##STR00029##
[0197] The resulting epoxy resin had an epoxy equivalent of 262
g/eq.
Synthesis Example 4
Synthesis of compound of Japanese Unexamined Patent Application,
First Publication No. Hei 8-301980
[0198] In a 500 ml four-necked flask, 166 g (1.0 mols) of
p-xylylene glycol dimethyl ether, 42.5 g (0.25 mols) of diphenyl
ether and 12.5 g of p-toluenesulfonic acid were charged and then
reacted in a nitrogen gas flow at 150.degree. C. while stirring.
Methanol produced during the reaction was removed out of the
system. After about 3 hours, when 16 g of methanol was produced,
202.5 g (1.88 mols) of o-cresol was added and the reaction was
further conducted at 150.degree. C. for 2 hours. Subsequently,
methanol produced during the reaction was removed out of the
system. After the completion of the production of methanol, the
reaction solution was neutralized with sodium carbonate and excess
o-cresol was distilled off to obtain 237.5 g of a phenol resin
(B-10). The resulting phenol resin had a softening point of
100.degree. C. (B&R method), a melt viscosity (measuring
method: ICI viscometer method, measured temperature: 150.degree.
C.) of 19 dPas and a hydroxyl group equivalent of 249 g/eq.
[0199] In the same manner as in Example 9, except that 249 g/eq
(hydroxyl group: 1 equivalent) of a phenol resin obtained by the
above method was used in place of the phenol resin (A-1), the
epoxydation reaction was carried out to obtain an epoxy resin
(E-7). The resulting epoxy resin had a softening point of
79.degree. C. (B&R method) and an epoxy equivalent of 421
g/eq.
Examples 13 to 31 and Comparative Examples 1 to 3
[0200] Using the above epoxy resins (E-1) to (E-6), YX-4000H
(tetramethyl biphenol type epoxy resin, epoxy equivalent: 195 g/eq)
manufactured by Japan Epoxy Resins Co., Ltd., NC-3000 (biphenyl
novolak type epoxy resin, epoxy equivalent: 274 g/eq) manufactured
by Nippon Kayaku Co., Ltd. and EXA-4700 (naphthalene type epoxy
resin, epoxy equivalent: 164 g/eq) manufactured by DAINIPPON INK
& CHEMICALS Co., Ltd. as the epoxy resin; the avove phenol
resins (A-1) to (A-8), XLC-LL (phenol aralkyl resin, hydroxyl group
equivalent: 176 g/eq) manufactured by Mitsui Chemicals Co., Ltd.
and MEH-7851SS (biphenyl novolak resin, hydroxyl group equivalent:
200 g/eq) manufactured by Meiwa Plastic Industries, Ltd. as the
phenol resin; a comparative epoxy resin E-7; a comparative phenol
resin A-9; triphenylphosphine (TPP) as the curing accelerator;
condensed phosphate ester (PX-200, manufactured by Daihachi
Chemical Industry Co., Ltd.) and magnesium hydroxide (Echomag Z-10,
manufactured by Air Water Inc.) as the flame retardant; spherical
silica (S--COL, manufactured by Micron Co., Ltd.) as the inorganic
filler; .gamma.-glycidoxytriethoxysilane (KBM-403, manufactured by
SHIN-ETSU CHEMICAL CO., LTD.) as the silane coupling agent;
carnauba wax (PEARL WAX No. 1-P, manufactured by Cerarica Noda Co.
Ltd.); and carbon black according to the formulations shown in
Tables 1 to 3, these components were melt-kneaded at a temperature
of 85.degree. C. for 5 minutes using a twin roll to obtain the
objective compositions, and then curability was evaluated. Physical
properties of the cured article were evaluated by the following
procedure. That is, samples for evaluation were produced by the
following method using the above compositions, and then heat
resistance, flame retardancy and dielectric characteristics were
determined by the following method. The results are shown in Tables
1 to 2.
<Heat Resistance>
[0201] Glass transition temperature was measured using a
viscoelasticity measuring apparatus (solid viscoelasticity
measuring apparatus RSAII manufactured by Rheometric Co., double
cantilever method; frequency: 1 Hz, temperature raising rate:
3.degree. C./min).
<Curability>
[0202] 0.15 g of each epoxy resin composition was placed on a cure
plate (manufactured by THERMO ELECTRIC Co., Ltd.) heated to
175.degree. C. and time measurement was initiated using a stop
watch. The sample was uniformly stirred using a bar. When it became
possible to cut the sample into the form of string and they were
remained on the plate, the stop watch was stopped. The time
required for the sample to be cut and remained on the plate was
taken as a gel time.
<Flame Retardancy>
[0203] Samples for evaluation, each measuring 12.7 mm in width, 127
mm in length and 1.6 mm in thickness were obtained by molding at a
temperature of 175.degree. C. for 90 seconds using a transfer
molding machine and by curing at a temperature of 175.degree. C.
for 5 hours. Using 5 test samples having a thickness of 1.6 mm thus
obtained, a combustion test was conducted in accordance with a
UL-94 test method.
<Measurement of Dielectric Characteristics>
[0204] Samples for evaluation, each measuring 25 mm in width, 75 mm
in length and 2.0 mm in thickness were obtained by molding at a
temperature of 175.degree. C. for 90 seconds using a transfer
molding machine and curing at a temperature of 175.degree. C. for 5
hours. Each of test samples thus obtained was bone-dried and then
stored in a room at 23.degree. C. and a humidity of 50% for 24
hours to obtain a cured article. The dielectric constant and
dielectric dissipation factor at a frequency of 100 MHz of the
resulting cured article were measured by a method defined in
JIS-C-6481 using an impedance material analyzer "HP4291B"
manufactured by Agilent Technology Co., Ltd.
TABLE-US-00001 TABLE 1 Formulation of epoxy resin composition
(parts by mass) and evaluation results Examples 13 14 15 16 17 18
19 20 21 22 Epoxy E-1 79 75 E-2 71 72 67 66 E-3 83 84 83 E-4 84
Curing agent A-5 62 50 XLC-LL 55 63 51 50 51 58 MEH-7851SS 59 67
Condensed phosphate ester 30 Magnesium hydroxide 30 30 TPP 3 3 3 3
3 3 3 3 3 3 Fused silica 850 850 850 850 850 850 850 820 820 830
Coupling agent 5 5 5 5 5 5 5 5 5 5 Carnauba wax 5 5 5 5 5 5 5 5 5 5
Carbon black 3 3 3 3 3 3 3 3 3 3 Curability 25 38 20 27 31 33 35 28
29 20 Heat resistance 132 122 151 133 144 128 126 141 144 134 Class
of combustion test V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 1* 4 3 5
4 5 4 7 4 3 3 2* 18 14 23 18 21 16 24 16 13 11 Dielectric constant
2.87 2.85 2.98 2.91 2.87 2.80 2.84 2.98 2.91 3.03 Dielectric
dissipation factor 75 70 96 85 75 61 64 98 92 100
(.times.10.sup.-4)
TABLE-US-00002 TABLE 2 Formulation of epoxy resin composition
(parts by mass) and evaluation results Examples 23 24 25 26 27 28
29 30 31 Epoxy E-2 E-3 58 54 57 E-5 24 61 73 46 61 57 E-6 25
NC-3000 YX- 19 20 4000H EXA- 23 43 4700 Curing A-3 61 72 58 agent
A-5 43 A-7 73 A-8 77 XLC-LL 52 57 53 MEH- 7851SS Condensed
phosphate ester Magnesium 30 hydroxide TPP 3 3 3 3 3 3 3 3 3 Fused
silica 850 850 850 820 850 850 850 850 820 Coupling agent 5 5 5 5 5
5 5 5 5 Carnauba wax 5 5 5 5 5 5 5 5 5 Carbon black 3 3 3 3 3 3 3 3
3 Curability 34 26 28 23 26 22 31 37 39 Heat resistance 157 164 133
127 120 161 122 128 125 Class of V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0
V-0 combustion test 1* 6 6 6 6 5 4 7 3 3 2* 26 31 29 25 23 20 36 15
13 Dielectric 2.89 3.01 2.92 2.89 2.98 2.96 2.88 2.83 2.80 constant
Dielectric 93 87 87 81 87 85 84 64 61 dissipation factor
(.times.10.sup.-4)
TABLE-US-00003 TABLE 3 Formulation of epoxy resin composition
(parts by mass) and evaluation results Comparative Examples 1 2 3
Epoxy E-5 81 E-7 94 NC-3000 85 Curing agent A-9 49 53 XLC-LL 40 TPP
3 3 3 Fused silica 850 850 850 Coupling agent 5 5 5 Carnauba wax 5
5 5 Carbon black 3 3 3 Curability 50 47 54 Heat resistance 120 131
125 Class of combustion test V-1 V-1 *3 1* 18 23 37 2* 107 146 143
Dielectric constant 3.05 3.14 3.27 Dielectric dissipation factor
(.times.10.sup.-4) 103 125 135 Notes of Tables 1 and 2: *1: Maximum
flame maintenance time for a single flame contact (seconds) *2:
Total flame maintenance time of 5 test samples (seconds) Notes of
Table 3: *1: Maximum flame maintenance time for a single flame
contact (seconds) *2: Total flame maintenance time of 5 test
samples (seconds) *3: Samples do not satisfy flame retardancy
(.SIGMA.F .ltoreq. 250 seconds and F.sub.max .ltoreq. 30 seconds)
required for V-1, but none of samples shows any ignition (arrival
of flame at a clamp)while all resulted in extinction.
INDUSTRIAL APPLICABILITY
[0205] According to the present invention, there can be provided an
epoxy resin composition capable of realizing low dielectric
constant and low dielectric dissipation factor, which is suited for
use as a latest high-frequency type electronic component-related
material, while maintaining excellent heat resistance of a cured
article thereof, and a cured article thereof, a novel phenol resin
which imparts these performances, and a novel epoxy resin.
* * * * *